Elementary Wiki
Elementary Wiki

I am better with you, Watson. I'm sharper, I'm more focused. Difficult to say why, exactly. Perhaps in time, I'll solve that as well.

— Holmes, "Details"

Joan Watson (born Joan Yun, Chinese name Yun Jingyi, on December 3, 1968) is a consulting detective for the 11th Precinct and Scotland Yard along with her partner, Sherlock Holmes. Once a surgeon, she became a sober companion and in this capacity was hired by Sherlock's father, Morland, after Sherlock finished drug rehabilitation. When her contract ran out, she became Sherlock's apprentice. Possessing a brilliant deductive mind, Watson's medical background and empathy are invaluable assets in crime solving. She likes baseball, studies the mafia and takes care of Clyde.



S01E05-Watson as a doctor

Joan is the daughter of Mary Watson and sister of Oren. Her birth father suffers from schizophrenia and left Mary, who later married Henry Watson. Joan has a half sister, Lin Wen. Joan was valedictorian of her class in medical school.[1] When a surgical resident, she became romantically involved with a patient who became a drug addict, who she tried to help. When a surgeon, she accidentally killed a patient, Gerald Castoro, and was suspended for two months. Having lost confidence as a surgeon, she let her medical license expire.[2] Having learned how to deal with addicts, she decided to become a sober companion.

Season 1[]

You make an effort to appear conventional, but I know, Watson, you share my love of all that is bizarre and outside the humdrum routine of ordinary life.

— Holmes, "The Leviathan"
S01E01-Watson baseball hat

Joan Watson Season One/Gallery

Watson becomes the sober companion to Sherlock Holmes, meets Captain Gregson, learns about Holmes' work and his eccentric nature. Watson deals with Holmes meddling with her relationship with Ty Morstan and gets Holmes to realize he's cut himself off from relationships as a penance for his drug use. A case of a child predator and his protégé sees Holmes start to use Watson as a sounding board while investigating. While going on several dates with Aaron Ward, who Emily Hankins set her up with, Watson saves Holmes from a murderous secretary and reveals Holmes' addiction to Gregson. She's instrumental in finding an angel of death at a hospital but puts practising medicine aside. Watson sees through a prank Holmes plays on her with his friend Alistair and asks Holmes about Irene. Pushing Holmes to select a sobriety sponsor, he chooses Alfredo Llamosa to spite her. Watson deals with an ex-lover, Liam Danow. Watson is pleasantly surprised when Holmes lauds her to her mother Mary and brother Oren. Watson builds her first evidence wall to prove Russian spy handler Geoffrey Silver committed murder. Seeing the impact that discovering Moriarty, not Sebastian Moran, killed Irene has on Holmes, leads Watson to lie that her contract has been extended. Watson deals with Rhys Kinlan, Holmes' former drug supplier, and apprehends a corrupt DEA agent. While investigating a drive-by shooting on Detective Bell, Watson agrees to become Holmes' apprentice and moves into the Brownstone. After finding Irene, Holmes is nearly killed by Isaac Proctor and discovers that Irene is Moriarty. Despite being warned by her to not oppose her plans, Watson figures out why Moriarty won't kill Holmes and they are able to trick, and capture her.

Appearances in Season 1
"Pilot": When Watson meets Holmes, he claims he needs no help to stay sober, as he tells her he is done with drugs. He suggests she should take the six weeks she's supposed to be his sober companion, and spend them as a holiday instead. After a fight, Watson says she'll request a new sober companion for him, but she later changes her mind and stays after Holmes apologizes. According to Holmes, she hates her job as a sober companion, but loves what he does. She denies this, but he claims that someone who needs two alarm clocks to wake up in the morning, is not enjoying her job.
"While You Were Sleeping": Holmes and Watson attend his first addict group support meeting. She notices that he is staring straight ahead, almost as if asleep. Watson's dinner with her ex, Ty Morstan, doesn't go well as he expresses worry about her current career and that Watson's parents contacted him with similar concerns. Watson asks why Holmes didn't tell Captain Gregson he was in rehab. Holmes believes Gregson wouldn't let a recovering addict work on sensitive cases and threatens to sue Watson if she tells Gregson. As Watson participates in the case of Rebecca and Yvette Ellison, she is surprised to find Ty waiting outside the Brownstone. Holmes is meddling in her life and has invited Ty to a supposed party. Watson walks an angry Ty away and then turns on Holmes. He proposes that they stay out of each other's personal lives. Watson is able to influence Holmes to play his violin and deal with closing himself off to relationships as a form of penance for his drug use.
"Child Predator": While searching for the van used by child predator "The Balloon Man", Watson complains about a shushing from Holmes. He explains that thinking out loud helps his thought process as long as the subject is silent. As Watson protests and comments on his lack of sleep, Holmes takes back his comments. Watson's natterings have helped him identified a parked car which has been side-swiped, leaving brown and blue paint. At the 11th Precinct, Holmes tells Watson to not to be offended by his earlier words and that having her as a sounding board is useful. Seeing Holmes go days without sleep, Watson gets Holmes to exercise. The next morning, Holmes wakes Watson and reports that the FBI believed The Balloon Man was an exterminator until not finding any strong suspects. Holmes believes he changed jobs between the third and fourth victims to delivering a nightly newspaper. After capturing "The Balloon Man", Samuel Abbott, back pain from the exercise provides Holmes with the break-through to capture his protégé, Adam Kemper.
"The Rat Race": Watson is at lunch with Emily Hankins who has arranged a surprise date for her with a work friend, Aaron Ward. Both feeling awkward, they laugh at the situation and begin talking until Watson is interrupted by a text from Holmes, filled with text jargon, demanding her presence. She accompanies him to Canon-Ebersol, a large investment firm, and follows him as he begins investigating the disappearance of executive Peter Talbott. Watson is angry to learn that while she was in the bathroom at the restaurant, Holmes used her phone to accept a date from Ward. In a high-end apartment, they find Talbott dead in an easy chair, with a syringe sticking out of his arm. With Gregson and Detective Bell on the scene, Watson worries about Holmes' sobriety as Talbott OD'd on heroin. Watson has a good time on her date but when she returns home, tells Holmes that she suspects Aaron was lying about having never been married. Reluctant to confirm her suspicions, Holmes does an internet search and discovers to Watson's anger that Aaron is currently married. Aaron explains to Watson that his marriage was to save a woman from being deported and killed. They don't live together and plan to divorce once she can remain in the US on her own. Watson is impressed until Aaron asks how she found out he was married. After Holmes is kidnapped by Donna Kaplan, a murderous secretary at Canon-Ebersol, Watson is able to deduce that a text sent from Holmes' phone wasn't sent by him and brings police to the location where Kaplan plans to kill Holmes. She's able to draw a compliment from Holmes for saving his life but she says that she had to reveal Holmes' addiction to Gregson. The next morning, Watson gets a text from Aaron, declining that they attend a party at Emily's together. Watson can't believe that he is peeved that she uncovered his lie.
"Lesser Evils": In a hospital morgue, Holmes chokes a corpse to study bruising while Watson looks on. Holmes believes the man was murdered by ephenephrine poisoning. After Holmes shows Watson a photo of a wound on the man's body that proves he was poisoned, he examines the hospital room the man was in. With security guards pounding on the door, Watson confirms that the IV machine's rate was lowered to prolong the poison's effect. Holmes and Watson meet Dr. Carrie Dwyer, an old colleague of Watson's. Dwyer asks if Watson is applying for a position at the hospital and Holmes discovers her medical license suspension was only for a few months. Holmes and Watson reveal to Dr. Baldwin that Trent Kelty's autopsy revealed he was killed with ephenephrine and that a murderer is at work in the hospital. Poring over hospital records, Watson shows Holmes another drug source, hospital crash carts. Working together, they find nine patients who died when ephenephrine went missing from the carts. Asked to consult on a patient by Dwyer, Watson has to press several times for Dwyer to perform a test on the patient which reveals endocarditis. Holmes also remarks that catching a glimpse of Watson in her former element was quite enlightening, and perhaps she will return to it one day. In her room, Watson browses through photos on her tablet of herself and her friends from when she was a doctor. She selects them all for deletion, hesitates at the confirmation prompt and then presses "Yes."
"Flight Risk": When Sherlock's father Morland invites her and Sherlock out to dinner, Sherlock tells her that his father never shows up. She decides to go anyway, and at the restaurant she meets a man posing as Sherlock's father. Joan believes it is Morland at first, but when he starts asking strange questions, she knows something is up. The man turns out to be Sherlock's friend Alistair, a struggling actor, although he states Sherlock only hired him through his agent and that they've never met before. Watson later shows up at the bookstore Alistair works at, and asks him to tell her about Holmes' past. She learns about his addiction and a woman named Irene. When she returns home, she asks Sherlock about her.
"One Way to Get Off": Angry that Watson is prying into his past, Holmes does his best to avoid her. Watson visits the rehab centre Holmes attended, Hemdale Recovery Center, the groundskeeper Edison gives Watson letters that Holmes left behind. Holmes later tells Watson that Irene died.
"The Long Fuse": Watson pushes Holmes to choose a sobriety sponsor and he rejects Adrian, a candidate she lines up. After visiting the offices of Vanowen Strategic Communications, whose old office was bombed, at a support group meeting, She reminds him about finding a sponsor and to her surprise, he picks the person speaking, Alfredo Llamosa, a former car thief. Watson and Alfredo wait for Holmes at a coffee shop but he texts that he can't make it. Alfredo advises patience and his calm demeanor surprises Watson given his gang appearance. He says he can help Holmes once given the chance. Watson indicates that Alfredo was fine with rescheduling their meeting which surprises Holmes. Watson mentions a coffee meeting with Alfredo the next day, but Holmes says he's decided Alfredo won't make a good sponsor. Watson accuses Holmes of not wanting to find a sponsor so she won't leave and that he never expected her to approve of Alfredo. That evening at the Brownstone, Holmes is surprised when Alfredo shows up at the front door. He says he understands if Holmes is not ready to accept him as a sponsor, but he is there for another reason. Alfredo points to a gleaming Ferrari parked on the street and says that, because of his expertise as an auto thief, he is regularly employed by car companies to test their new security systems. He invites Holmes to try his luck breaking in but when Holmes demurs, he appeals to Holmes' vanity. Holmes looks at Watson, knowing she put Alfredo up to finding common ground they could bond over.
"You Do It to Yourself": Watson receives a call and goes to Rikers Island Prison to help an old client. At Rikers, Watson meets Liam Danow, a recovering addict. He's been arrested for a hit-and-run that he swears someone else committed with his car. He admits that he was high that night, but would have remembered. He asks Watson to help with her friend at the D.A.'s office, but she refuses. As she leaves, he asks if she treats all her ex-lovers this badly. Watson discusses Liam's case with Holmes and notes that his car was wrecked but Liam had no injuries. She believes he's telling the truth and Holmes tells her of numerous car thefts in Liam's neighborhood where the cars were hot-wired and stripped of valuables. Watson believes Liam left the keys in the car and notes a key-ring pendant she gave him was missing. Holmes has deduced that Liam was Watson's ex-lover and Watson evades his questions due to embarrassment. At Rikers, Watson shows Liam the crime scene photos of his car. He apologizes for his unkind words and she asks him why he keeps repeating his past mistakes and using drugs. Liam notices that the keychain Watson gave him is gone. Watson reports that she found the pawn shop where Liam's stolen keychain was sold to and the owner knew the man who brought it in. Once he's found, Liam will be released. Holmes compliments her and she confesses that Liam was never a client. She met him when she was a doctor, his head was smashed when he defended a woman who was mugged. They became lovers and he turned to drugs later. She unsuccessfully tried to help him but learned much about being a sober companion in the process. At Rikers, Watson shows Liam a news article in which his car thief has been arrested which clears him of the hit-and-run. Liam is grateful, but Watson says she won't bail him out anymore. She's made an appointment at a rehab clinic and leaves it with him.
"The Leviathan": Watson assists Holmes with a robbery involving a supposedly impregnable vault called "The Leviathan" during which Holmes wakes Watson three times. She accuses him of obsessive behaviour and points out she needs to leave to prepare for brunch with her mother, Mary. Watson meets her mother for brunch who informs her that her brother Oren and his girlfriend are in town and they'll be having dinner that evening. Joan reminds her mother that she can't come while working as a companion. Mary decries Joan's job but she's interrupted by a call from Holmes asking her to meet him at Sing Sing. Watson receives a call from Oren who is excited to see her and her client at dinner. Watson didn't send the text but says they'll be there and then turns on Holmes. He confesses how easy it was to break into her phone and says he feels a relapse coming on which forces Watson to be with him. Watson reminds Holmes of their dinner but he begs off to work on the case which Watson agrees to, relieved. Watson arrives at the restaurant and is surprised to find Holmes already there. He's been regaling her family with stories of how Joan helped him on various cases and that she's a promising detective. He also lauds her work as a sober companion which impresses Mary. In a taxi on their way home, Watson thanks Holmes for making her family understand what she does. Later at the Brownstone, Holmes lets Mary Watson in. Speaking in private with Joan, Mary says that she has never made a secret of her disapproval of Joan's new career but she noticed a spark in Joan that she hasn't seen since her days as a surgeon. She suggests that Joan likes what Holmes does but she Joan demurs. Mary asks if continuing as a sober companion will make her happy and points out that people find their path in all sorts of ways.
"Dirty Laundry": The murder of Teri Purcell leads Watson and Holmes to find she and her husband Oliver are Russian spies and Teri was killed by their handler, Geoffrey Silver, in order that Teri and Oliver's daughter, Carly, would also become a spy. Watson counsels Carly several times as she deals with guilt surrounding her mother's death. Watson is instrumental in finding Silver guilty and builds her first evidence wall. Holmes is disappointed to discover that Watson doesn't intend to become a detective and has already lined up another client.
"M.": Watson meets her therapist, Dr. Candace Reed, who is concerned that Watson is having trouble moving on from Holmes. Watson admits that she finds his work fascinating and will miss their time together. Watson meets one of Holmes' "Irregulars", Teddy, and confront Holmes when she learns he has hidden cameras in the Brownstone. Learning that he intends to capture and kill "M.", aka Sebastian Moran, a serial killer he holds responsible for Irene's murder, Watson appeals to Holmes to not pursue vengeance, without success. He warns her not to follow him, but she says that as soon as he leaves, she'll go to Gregson. Gregson is furious at Watson's news. Watson shares what Holmes has deduced about M but that he's not likely at his hotel as Holmes may have already abducted him. She provides Gregson with the address of one of Morland's properties in which Moran is found, after being tortured by Holmes. Seeing the impact that discovering Moriarty, not Moran, killed Irene has on Holmes, Watson lies that her contract with him has been extended.
"The Red Team": Watson attends a therapy session with Dr. Reed and confesses the lie she made to Holmes. Reed wonders why Watson is staying with him while not being paid so she explains her concerns and that she'd like to heal the rift between Holmes and Captain Gregson. At the home of Len Pontecorvo, aka "Zapruder", Holmes explains that he's the moderator of an online conspiracy theorist chat room and was absent. After Holmes picks the lock, they find Pontecorvo has been hung. Over Watson's protests, Holmes finds Len's binders on conspiracy theories and decides to take them. He also decides to take Len's pet tortoise Clyde, to prevent him from starving. Watson is touched until Holmes says he'll make a delicious soup. While Holmes investigates one of Len's theories involving US Army war game group, the "Red Team", Watson pleads with Gregson to give Holmes a second chance but he can't forgive that Holmes nearly murdered Moran while working for him and believes Holmes isn't repentant. After Holmes solves Len's murder, at the Brownstone, Holmes is sipping from a bowl of soup when Watson enters the kitchen. She's worried Holmes has cooked Clyde but Holmes places him on the table and expresses his admiration for tortoises. She can't get Holmes to talk about what happened with Gregson and remarks on Holmes' unpredictability.
"The Deductionist": Although Watson lived with her clients when she was a sober companion, she had her own apartment. She's evicted from her apartment after the man she sub-let it to, Cooper, filmed a pornographic film there. Assisting Holmes with tracking escaped serial killer Howard Ennis, Watson realizes that his sister Patricia, helped him escape so they could exact revenge on Kathryn Drummond. Watson returns to her apartment where her landlord Bruce apologizes for having to evict her. Watson tells him that when she was watched the porn, she noticed that the tape on the radiator appeared and disappeared. She found the actors, who confirmed that Bruce was in the apartment while it was being shot and fixed the radiator. As her apartment is rent-controlled, he could charge higher rent if he was able to evict her. Participating in unlicensed filming is a crime which makes Bruce give in. Watson demands that he and Cooper put her things in storage and pay for a new couch to replace the one used liberally in the movie.
"A Giant Gun, Filled with Drugs": When Holmes' ex-drug dealer Rhys Kinlan comes to him for help finding his kidnapped daughter, Emily, Watson becomes worried that Holmes will be tempted to start doing drugs again. Unable to find Emily, Holmes secures the ransom money from his father. After Holmes has left for the exchange meeting, Watson answers the door to find DEA Agent Xande Diaz. He has new information about the kidnapping and needs to speak with Holmes urgently. The exchange meeting is a trap and Diaz ties up Watson and Rhys. Rhys cuts himself and Watson loose, then charges unarmed into the living room, where Diaz fires. Shot in the stomach, Rhys still manages to tackle Diaz to the ground. While Rhys grapples with Diaz on the floor, Watson grabs Sherlock's phrenology bust Angus and smashes it over Diaz's head, knocking him unconscious. After Diaz is arrested and Emily found, Holmes initiates attending a support group meeting with Watson.
"Details": While investigating a drive-by shooting on Detective Bell, Watson meets with her therapist, Dr. Reed, who is shocked to hear she was held at gunpoint and insists on staying with Holmes, without pay, and maintaining the fiction that she's his sober companion. She's concerned for Watson's safety and believes if Holmes was too, he would be telling her to move on, not trying to train her. Holmes reveals he has known that Watson stayed on as his sober companion even though his father didn't extend her contract. He tells her he is grateful that she stayed when he needed it, but claims that after some time, she stayed for herself as well, and proposes again that she should become his apprentice. She later accepts, moves into the Brownstone and Holmes starts training her.
"Possibility Two": At a crime scene, two security guards are lying next to each other in a parking lot, shot dead. Watson, in her new role as Holmes' apprentice, attempts to reconstruct what transpired and which direction the shooter went. They're approached by a limo driver, Crabtree, who asks them to speak to his employer, Gerald Lydon, CEO of a large corporation. Lydon is convinced he's been poisoned with a genetic disease, CAA. Holmes turns down his case until Lydon kills Crabtree and can't remember doing it. He accepts a rare bee as payment. While investigating, Holmes repeatedly sends Watson to a dry cleaners, Main Moon. Holmes and Watson find that the head of a genetic research company, Brian Watt, has CAA and poisoned several rich people with it so they would donate to finding a cure. Holmes praises Watson after she deduces that Main Moon is a front for crime and she has Bell arrest the staff.
"Déjà Vu All Over Again": Holmes gives Watson her first case to investigate without his help, the disappearance of Callie Burrell. Convinced that her husband Drew Gardner is responsible, Holmes shows her a technique known as "gaslighting" to try and entrap him. Holmes has to bail Watson out of jail after she's caught breaking into Drew's van. With Holmes' help, Watson finds evidence that Drew did kill Callie by copying a past murder that Callie referred to in a video.
"Snow Angels": During a snowstorm that shuts down NYC, Holmes and Watson find that a shooting and robbery of new phones is a cover for a heist at EROC (East Rutherford Operations Center), which contains the world's largest supply of U.S. cash. With the help of snow plow driver Pam, they eventually trap the thieves. Watson meets Ms. Hudson who Holmes employs as their part-time maid.
"Dead Man's Switch": On the anniversary of his first year of sobriety, Holmes refuses to celebrate. He first claims it is pointless, as to him it doesn't celebrate a period of success, but rather the end of a period of great failure. He later reveals to Watson that he can't celebrate his anniversary because he had used drugs the day after he had agreed to enter rehabilitation, therefore, his anniversary wasn't really his real anniversary, but the day after. Watson gives Holmes a present to celebrate, a framed poem. He and Watson also ends the careers of several blackmailers as a result of Alfredo's sobriety sponsor's daughter being subjected to threats.
"A Landmark Story": At Newgate Prison, Moran tells Holmes that councilman Van Der Hoff was murdered by Moriarty's organization. After breaking into a funeral home with Watson and performing an autopsy on Van Der Hoff, Holmes deduces that Hoff's pacemaker was used to kill him. Finding the motive for Van Der Hoff's death, Holmes discovers that a meticulous killer is murdering those opposed to preserving a building's landmark status. He and Watson capture the killer, Daniel Gottlieb, aka "The Actuary." They learn he's working for Moriarty and Holmes is able to find the man who recruited Gottlieb, John Douglas, who is killed by a sniper. At the precinct, Gottlieb confesses to numerous murders and receives a coded message on his phone. Holmes shows Moran the message, who claims not to know what it says. Holmes is able to decode it the message, which blackmails Moran into suicide, but not in time to save Moran, who kills himself. Knowing he's been outsmarted several times by Moriarty and that he could have been shot by the sniper when meeting Douglas, Holmes tries to deduce Moriarty's game. Gottlieb's phone rings which Holmes puts on speaker while Watson records the call. The caller, with a British accent, introduces himself as Moriarty and indicates that they are overdue for a chat.
"Risk Management": Moriarty tells Holmes and Watson to find the killer of a man named Wallace Rourke, bring the killer to justice and he'll answers all Holmes' questions on what happened to Irene. They prove that Katie Suter tricked her husband Darren into murdering Rourke. Leaving Katie's office, Holmes believes Moriarty's motive in assigning him the case was to demonstrate the cost of vengeance. Holmes receives a call from Moriarty congratulating him and texts him an address that will provide answers about Irene. If Holmes doesn't go to the address, he promises their paths will never cross again and is curious what Holmes will choose to do. The address Moriarty provided is a large estate. About to enter, Watson arrives having cloned the phone that Moriarty called on. Approaching the mansion, they find a key in the front door and enter. Searching through empty rooms, Holmes beckons Watson towards a solarium where he hears music. The solarium is crowded with paintings of scenes Holmes recognizes. His face trembling, he nearly collapses and points towards a woman painting. Calling out her name, Irene Adler turns around.
"The Woman": Appearing as if she has been held captive, Irene is checked into a hospital where her doctor tells Holmes, Watson and Captain Gregson that her personality has been destroyed by a masked man who she called Mr. Stapleton. They bring Irene to the Brownstone and settle her in Holmes' bedroom. In private, Watson offers her help and expresses concern about Holmes' sobriety. Assuring her that he is fine and will be dedicating himself to caring for Irene, he encourages her to consult on her own. At the mansion where Adler was found, she meets with Gregson and Detective Bell. They report the house is clean and the owner is 9 year old Austrian heir. Watson examines pigments Adler was using in her paintings and discovers a rare sample that only a few shops in NYC sell. This leads to the police in finding an assassin in Moriarty's employ, Isaac Proctor. Holmes is shot by Isaac who in turn is killed by Irene who Holmes realizes is Moriarty.
"Heroine": After Moriarty warns Holmes to not interfere in her plans, Watson stitches up Holmes' gunshot wound. After meeting with Moriarty, Watson is able to figure out why she won't kill Holmes. Holmes fakes an overdose, and when Moriarty visits him in the hospital, he records their conversation, getting her confession to murder on tape. He and Watson foil Moriarty's plan to make billions by manipulating an agreement between Greece and Macedonia. Holmes also discovers a new species of bee which he names Euglossa Watsonia, after Watson.

Season 2[]

You know you're starting to sound like your partner.

S02E13-Watson formal dress

Joan Watson Season Two/Gallery

Holmes and Watson visit London to find Gareth Lestrade and deal with Sherlock's brother, Mycroft who is living at 221B Baker St. Watson deals with Joey Castoro, the son of Gerald, who she accidentally killed during surgery. Watson fights the hacker collective "Everyone" and begins writing "The Casebook of Sherlock Holmes." Watson meets Dr. Eugene Hawes and learns Holmes slept with her friend Jennifer when she was his sober companion. Holmes gives Watson a box with files on cases he hasn't been able to solve. Sherlock becomes protective of Watson when learning she slept with Mycroft and she assists in a case involving Nigella Mason. Watson assists in thwarting serial killer Lucas Bundsch and addresses Holmes' rudeness. Holmes and Watson are subjected to an administrative hearing pertaining to a case in which Detective Bell is shot. A case involving one of Moriarty's lieutenants, Devon Gaspar, sees Holmes and Watson involved in a kidnapping of Moriarty's biological daughter, Kayden Fuller. Watson employs her first "Irregular", Gay, in a case involving a dinosaur skeleton. Watson frees several veterans being held prisoner in a basement and tells Holmes that her biological father is homeless and schizophrenic. Watson deals with Lestrade and two roosters, Romulus and Remus, while catching a bomber. Watson tells Sherlock she intends to move out of the Brownstone and is kidnapped by Marchef, a member of "Le Milieu", a French crime syndicate. Watson is rescued by Mycroft who reveals he works for MI6. While working on a case involving Arthur West, Watson discovers Mycroft made an incredible sacrifice for Sherlock and becomes romantically involved with him again. After thwarting attempts by Mycroft's handler, Tim Sherrington, to frame Mycroft as a mole, Mycroft goes into hiding and breaks Watson's heart. When Sherlock can't convince Watson to stay at the Brownstone, he accepts the offer of James Walter to work for MI6 and moves to London.

Appearances in Season 2
"Step Nine": After capturing an assassin of three U.S. Attorneys, a call on Holmes' phone results in him asking Watson to accompany him to London to help Gareth Lestrade, his old colleague. As they are packing, Holmes tells Watson his history with Lestrade. He calls him utterly adequate as a detective, but as credit for successes went to Lestrade, he began to crave the glory. At Scotland Yard, they are greeted by DCI Hopkins, Lestrade's superior. Describing the Mary Pendry case, in which Lestrade refused to let go of his suspicions and due to his extreme actions was suspended, Hopkins wants Holmes to find Lestrade. A cab delivers Holmes and Watson to 221B Baker St., Holmes's former residence in London. To his horror, he finds it has been totally remodelled and discovers that his brother Mycroft is living there. Sherlock finds Lestrade in a pub by tracking down various stashes of money that Lestrade knew about. Feeling guilty that he is responsible for Lestrade's addiction to fame, Sherlock agrees to look into the Pendry case. Sherlock finds that Mary's husband Lawrence did kill her using a plastic gun and is able to find evidence when Lawrence kills his handyman with the same weapon. Sherlock tells Lestrade that in order to break his addiction to fame, he is not to take credit for the arrest and if he does, Sherlock will discredit his involvement. The next morning, Sherlock and Watson see Lestrade on TV claiming the credit for Pendry's arrest. Mycroft texts Sherlock to meet him at a storage centre. He confesses that he didn't give away Sherlock's possessions but stored them at the centre. He says he learned from Watson that he must have Sherlock's attention when telling him something important and then blows up Sherlock's possessions using books on bomb building that were Sherlock's. Mycroft says he forgives Sherlock for everything and that things are different between them now.
"Solve for X": Watson visits the grave of Gerald Castoro, the man she accidentally killed during an operation. His son Joey Castoro arrives and presses her to have coffee with him. At a diner, Joey congratulates Joan on being a detective and she learns that he's dropped out of university, despite his father wanting him to become an engineer. Watson asks Holmes for an advance of $5000 to help Joey. He asks if she'd invest in a bar he's bought and applies some guilt tactics on Watson. She asks how much he needs. After mathematician Felix Soto is found murdered, Harlan Emple explains to Holmes and Watson that Soto was trying to solve P vs. NP. He indicates that another P vs NP expert, Tanya Barrett, may know who Soto's partner is. Questioning Barrett, Holmes finds the partner is Cyril Nauer who is found dead by Detective Bell. At the Morgue, Holmes recounts that Nauer was killed an hour after Soto and, by the same killer. Barrett becomes a suspect but when questioned, provides an alibi which is confirmed by time-stamped video. Confronting Barrett in her classroom, Holmes shows that she killed Soto and Nauer as they were close to solving P vs NP and she'd altered the security footage digital time stamp. Watson meets with Joey, and says she'll help him but will only pay for his education. Joey tries to guilt her into using the money for his bar but she remains firm.
"We Are Everyone": At the Brownstone, Holmes and Watson meet a new client, Mr. Mueller. Mueller says he represents a group of citizens concerned about Ezra Kleinfelter's safety, given that he has more secret documents he could leak. Mueller would like them to find and deliver Kleinfelter to him, so he can be taken to a friendly embassy. Holmes agrees to take the case and Mueller leaves. Having pick-pocketed a security guard's phone, who is connected to Ezra, Holmes discovers that he is a member of a cyber-activist collective "Everyone" and finds a message board, "Jamaica Quay." After Holmes wakes Watson, he reports that while debating on the board, he's deduced that a woman, Vanessa Hiskie, is hiding Kleinfelter. Watson picks the lock at Hiskie's apartment and they find her inside, dead. Having traced the security guard's phone to the Brownstone, Everyone subjects Holmes and Watson to a "life ruin". After discovering Ezra is leaving for Venezuela on a billionaire's jet, he arrested by Bell and Captain Gregson but is set free after threatening to reveal the identities of several deep cover federal agents. As Kleinfelter turns to board the plane, Watson grabs his wrist and warns him they will prove he killed Vanessa Hiskie. Watching the jet take-off, Watson produces Kleinfelter's wrist watch which she lifted from him. Impressed, Holmes asks Gregson to see if the DNA on the watch matches that found under Hiskie's fingernails. After Kleinfelter's arrest, Watson sits in bed with her laptop and begins writing "The Casebook of Sherlock Holmes."
"Poison Pen": Holmes and Watson are called to the home of Titus Delancey, CEO of a large financial firm, who was found dead in a bondage suit, by Mistress Felicia. Holmes discovers Titus was poisoned by nitroglycerin. Later, Holmes and Watson meet Titus' wife Peri and their nanny, Anne Barker. Holmes takes Watson outside and says that he knows her. She was the prime suspect in the poisoning death of her father, but was acquitted and her name was Abigail Spencer. In "the box" at the 11th Precinct, Gregson questions Anne who admits she was Abigail Spencer. She has no alibi but denies killing Titus. She changed her name and appearance to escape the media attention from her father's death, is angry that it will happen again and asks how they discovered her identity. Holmes says it was from her voice. Anne is released and Holmes believes that she is being framed. Watson deduces that Holmes didn't recognize Anne from her voice, but from a tattoo on her wrist. Impressed, Holmes relates that the poisoning of Anne's father catalyzed his interest in detective work. Holmes was able to deduce that she did kill her father, an abusive man, but only after the trial was over and she was acquitted. Despite this, he still believes that the framer must have discovered her past. Holmes visits Anne and reveals he is Sean Holmes. Beseiged by the media and fired as a nanny, she's still grateful to have Holmes to talk to. Bell and Watson find a tablet containing a video of Titus and Anne arguing.
"Ancient History": At a flea market, Watson and her friend Jennifer are shopping. Watson mentions that Holmes is bored, having no cases for weeks, and should introduce them one day. Hesitantly, Jennifer mentions she'd like to find a man she had a one-night stand with, Tony. Watson tells Holmes about Jennifer's request which he sees as demeaning. Pointing out that they are not busy, Holmes decides to find a case and takes Watson to the Morgue. Introducing her to Dr. Eugene Hawes, Holmes and Hawes play chess. Winning the game, Hawes gives Holmes access to the morgue's corpses. Hours later, Holmes comes upon the man who died in the motorcycle crash, Leo Banin. Holmes deduces that before Leo died, he killed someone. Watson visits the bar Jennifer met Tony at and discovers she met him on day of the Brazilian Parade. Holmes finds Watson about to watch a news tape showing the Brazilian Parade day at the bar. Unable to dissuade her, he admits that he is Tony. Shocked, she follows him to the kitchen where he explains that when she first started as his sober companion, he would follow her when she left for errands. Hoping to learn more about her, he saw her with Jennifer and passed himself off as Tony. He claims Jennifer seduced him and that once he found Watson's intentions as his sober companion were honorable, he stopped surveilling her. Later, Watson meets Jennifer to let her know that Tony was Holmes but she already knows. Holmes explained everything to her and so impressed, she slept with him again. However, Jennifer is totally over Holmes. At the Brownstone as Holmes practices with Bob, Watson unsuccessfully tries to scare Holmes that he's impregnated Jennifer.
"An Unnatural Arrangement": In the holding cells at the 11th Precinct, Holmes has Watson deduce what caused the prisoners to be jailed by examining them. After Captain Gregson's wife Cheryl is threatened during a home invasion, Holmes and Watson discover the attacker entered the wrong house. This leads them to pursue various members of a US military detail who were guarding an archaeological dig in Afghanistan led by Beth Roney. Roney stole various artifacts and with her ex-husband Cameron's help, tried to sell them. Holmes and Watson provide evidence her ex was behind the Gregson's home invasion and several others in which Cameron killed members of the military detail. Holmes gives Watson a box with files on cases he hasn't been able to solve.
"The Marchioness": Mycroft asks for help with an acquaintance of his and Sherlock's. At Diogenes, Sherlock is not happy to see the acquaintance and introduces Watson to Nigella Mason, Mycroft's former fiancée. Mason explains that after Mycroft, she married a Marquess. Not fulfilling his conjugal duties, she had an affair with Dalton, who was the stable master. The affair caused her divorce but she retained her title and a champion race horse, Silver Blaze. Dalton was killed by an intruder at the stables who intended to kill the horse and she'd like them to find Dalton's killer. Deducing that Mycroft and Watson slept together when they were in London, Sherlock is protective of Watson. Sherlock captures Dalton's killer, an assassin nicknamed "El Mecánico" and finds that Nigella's troubles were her own doing after she fraudulently passed off another horse as Silver Blaze for studding a drug king's mare.
"Blood Is Thicker": Sherlock and Watson solve a case involving the murder of tech billionaire Ian Gale and his estranged daughter Haley Taylor. Both were killed by Ian's doctor wife, Natalie, for his estate. Mycroft unsuccessfully tries to lure Sherlock to return to live in London after Sherlock discusses the possibility with Watson.
"On the Line": Holmes and Watson thwart serial killer Lucas Bundsch and frees several women being held captive while dealing with a disgruntled detective, Gerry Coventry. Holmes punches Bundsch and breaks his finger. Holmes discusses Watson's rebuking of his lack of politeness with others. Although he understands the social benefits, he indicates he is not a nice man, never will be and that being acerbic helps his work. Watson points out that he is often nice to her and that he has changed since they first met, but Holmes demands that she accept that there will always be fallout from his behaviour.
"Tremors": Holmes and Watson are subjected to an administrative hearing pertaining to a case in which Detective Bell is shot. Prosecutor Cassandra Walker accuses them of breaking the law in the course of investigations. As they recount the events in solving the murder of Silas Cole, Holmes' arrogance brings retribution from a suspect, James Dylan. As Dylan tries to shoot Holmes, Bell intervenes and is hit. Bell is partly responsible for the decision to allow Holmes and Watson to continue to work with the NYPD.
"Internal Audit": While investigating the murder of a corrupt hedge fund manager, Gerald Hauser, Watson re-meets Chloe Butler, who she was a sober companion to. Watson resists revealing Butler's past addiction, even though it would help the Hauser investigation. Holmes and Watson prove that Hauser was killed by Jacob Weiss, a charity CEO. Weiss and Hauser were partners in the scam but when Hauser's pyramid scheme was discovered, he told Weiss that he'd revealed the embezzlement.
"The Diabolical Kind": When a seven-year-old girl named Kayden Fuller is kidnapped and her father shot, Holmes and Watson hear the ransom demand. Holmes quickly recognizes the voice as that of the man who previously pretended to be Moriarty, who Moriarty herself described as one of her subordinates. Assuming Moriarty gave the order for the kidnapping, Holmes and Watson visit her at a prison black site. She's made a large painting of Watson's face in perfect detail. Moriarty denies being involved in the kidnapping, but offers to give information in exchange for prison favors. Holmes refuses, but shortly afterwards discovers she has been recruited as a consulting agent by her FBI handler, Ramses Mattoo, who bring her to work with the NYPD. Moriarty provides information on the kidnappers and is accompanied to the kidnapping scene by Watson. Moriarty admits she finds Watson more intelligent and interesting than at first, and that part of the reason that she and Holmes write to one another is because they are the only ones who can understand and relate to the other. When the kidnappers ambush and kill two policemen, Holmes believes Moriarty is somehow responsible. Devon Gaspar, one of the kidnappers and a former Moriarty lieutenant calls and puts a frightened Kayden on the phone. Watson notices that Moriarty is angry when listening to the call. Moriarty is returned to her prison cell. Holmes discovers code in the sketches Moriarty made of the kidnappers but is surprised to find that Moriarty isn't behind the kidnapping she's a victim as Kayden is her daughter. Moriarty escapes her prison using glass shards of her paint jars to neutralize her stun bracelets (cutting her wrists badly) and strangles Mattoo unconscious. She tracks Gasper and the kidnappers down in an old building she owns and kills them all. She calls the police and demands that Holmes be the only one sent into for her. She tells Holmes that Kayden has been re-situated and she placed her for adoption knowing that knowledge of Kayden's existence would make her vulnerable. Moriarty believes she will soon be free and thanks Holmes for his letters. She begins to pass out from blood loss so Holmes carries her outside for treatment where Watson believes she will recover.
"All in the Family": After Bell departs the 11th for Demographics, Holmes and Watson deal with a number of incompetent detectives, including Detective Nash. At a recycling plant, Bell finds a headless, handless body in a green barrel and calls for Gregson. Bell is icy towards Holmes so Watson excuses themselves. Holmes notes the barrel's original color was blue and from a scar on the man's leg, Watson knows who the man is. In Gregson's office, he's identified as former mobster Bobby Pardillo. At Demographics, Holmes offers his and Watson's services to Commissioner Frank Da Silva. Seeing Holmes, Bell is irked to learn Holmes will be working there when Holmes knows Bell doesn't want to see him. Holmes belittles Bell's new role as an analyst and leaves. At the home of a suspect, Dante Scalice, Holmes and Watson witness him die when his car explodes. Finding printouts at Scalice's which show Bobby's movements, Holmes recognizes them as from the NSA. Holmes and Watson confront Dean McNally who denies being part of the NSA. Later in private, McNally indicates to Holmes that Da Silva asked for the printouts. Finding evidence that Da Silva is corrupt and worked for the mafia, Holmes and Watson have a difficult time convincing Bell. After Bell finds further evidence that Da Silva is dirty, Bell and Holmes set a trap in which Da Silva is caught planning to murder a mob boss. Bell returns to the Major Cases unit and makes up with Holmes.
"Dead Clade Walking": At the Brownstone, Holmes is surprised to find a guest in the library, Gay. Watson explains that while examining Holmes' box of unsolved cases, she found the murder of Doug Newberg, in which a picture of his backyard had an unusual rock. Without permission, Watson and Gay enter Newberg's backyard and find the rock still there. Gay says the rock is from the dinosaur era and likely contains an archaeological specimen. Holmes meets Watson at the Morgue where a technician performs a CT scan on the rock. A complete skeleton of a small dinosaur is discovered inside it. At the Triboro Museum of Natural History, they meet with Dr. Jerome Thomas by a Dimetrodon skeleton which he indicates is the only complete one in the world. After the fossil is stolen from the precinct, Holmes meets with C. who informs him that a man known only as the "Magpie" buys rare, expensive items and that if Holmes posts such as item on a website, the Magpie will reach out to him. On the way to the "Magpie's" home, Holmes tells Watson that Randy isn't answering his phone. Finding the door open, they enter and discover a dead man and the nanotyrannus rock smashed on the floor. At the Brownstone, Holmes wakes Watson and believes he's found the motive for smashing the fossil, a theory called "Dead Clade Walking" (DCW). At the museum, Holmes and Watson confront Dr. Jerome Thomas and accuse him of destroying the fossil and committing the murders as the fossil's existence would discredit Thomas. He's served a warrant for his DNA to match that on a murder weapon.
"Corpse de Ballet": At the scene of a bisected ballerina, Nell Solange, Gregson leads Holmes and Watson through the crime scene and reports that the killer took the hard drive containing the security videos. A box cutter belonging to ballerina Iris Lanzer is the murder weapon. Questioning Lanzer, Holmes is uncharacteristically polite and deferential and, he offers explanations for many of his colleagues questions. Watson gets a call from a shelter she volunteers at that one of their clients is off his meds and had a run-in with the police. At the hospital, two officers explain their altercation with Morris Gilroy who is restrained in a bed. Gilroy yells that a sergeant named "Freebo" was taken. Watson calms him and promises to find Freebo. Watson identifies "Freebo" as former Army Sergeant Zeke Frebeaux and Bell agrees to distribute his picture to NYPD cars. Watson talks to Rachel Brown, who says she's Zeke's sister, at her house. Saying that Zeke has PTSD from service in Afghanistan and drug problems, she brought him home to care for him, but he wouldn't stay. She doesn't know where he is but as Watson indicates that she'll keep looking him, Brown expresses her gratitude. Gilroy is back on his meds, at a shelter and as Watson gathers clothing to bring there, Holmes asks why she's going to so much effort to help him. Watson reveals that her genetic father is schizophrenic and homeless. She volunteers at shelters hoping to see him. At the shelter, Gilroy tells Watson that he saw a white man rough Zeke up and take him away in a van. Watson indicates she hasn't found Zeke and his sister hasn't seen him. She looks through Zeke's bag and finds a pack of cigarettes which she noticed at Rachel Brown's. Looking at a family photo, Gilroy points to Zeke's sister who isn't Rachel Brown. At Rachel Brown's, Watson arrives with police and asks for Zeke. Rachel and her husband Cliff lie that Zeke isn't there. With a warrant, they enter and find a padlocked door. Zeke and two other men are found chained in the room. The Browns were collecting their veteran and disability checks.
"The One Percent Solution": "The One Percent Solution": At the Brownstone, Watson arrives and finds Holmes has broken up a cock fighting ring. He's feeding two roosters, Romulus and Remus and intends to experiment if they can be trained to stop fighting. Gregson calls them to the scene of the explosion which killed several people from the Dept. of Labor (DoL) and a bank whose CEO is Richard Balsille. Gregson informs them that Balsille has a "security czar" they'll have to work with which, to Holmes' revulsion, turns out to be Gareth Lestrade. Holmes discovers Lestrade is arranging sexual partners for his employer, CEO Richard Balsille, and catches the bomber, MoL staffer Michelle Forrester. Fired from his job, Lestrade asks if he can stay at the Brownstone while Holmes' experiment with the roosters is a success.
"Ears to You": His confidence shattered, Lestrade is mugged and has difficulty picking a new job, despite several offers. Encouraged by Watson to solve the case of his mugging, Watson and Holmes deal with a case involving Gordon Cushing, whose wife Sarah disappeared years before. Receiving a package containing Sarah's ears, a ransom demand goes wrong and Holmes and Watson are baffled to find Sarah alive, with her ears intact. They discover her new husband, a plastic surgeon, grew ears on her back which were removed and used in the ransom demand. After finding his mugger, Lestrade believes that Holmes doctored the case to boost his confidence and seeing through Holmes' "ruse" has done the trick and he's accepted one of his job offers. He threatens to stay unless Holmes admits to the charade. Holmes shakes his hand, congratulates Lestrade and heads to the kitchen. Confused, Watson follows and asks Holmes why he didn't let her in on his plan. Holmes honestly says he's never heard of the mugger nor seen the mugging file but wanted Lestrade to move on.
"The Hound of the Cancer Cells": After Barry Granger is murdered at a laboratory, the head of the lab, Hank Prince, shows Holmes and Watson what Granger was working on, a device called "The Hound" that could detect lung cancer from breath. Without Granger and combined with an anonymous tipster who refuted the device's test results, Prince is ruined. Later, they show Prince who was behind the fake allegation and that Granger's work has been cleared. Believing that he and Granger may be the victims of corporate sabotage, Prince provides them with a list of rivals to "The Hound." Prince's wife, who he was divorcing, is then found dead. They discover that Prince discredited the Hound and killed Granger, which would temporarily lower his company's value, so that his wife wouldn't receive as much in the settlement. Once Holmes and Watson cleared the allegation against "The Hound", Prince killed his wife so she wouldn't share in its value. After much reflection, Holmes meets Bell at a party celebrating Bell's return to active duty.
"The Many Mouths of Aaron Colville": Watson learns of a "vampire killer" who bites his victims from Detective Loughlin and remembers from her time as a surgeon, Aaron Colville, a serial killer who also bit. After taking a plea deal, Colville died in 2005 during a surgery Watson was a part of. She visits Dr. Jonathan Fleming, who refuses to tell her what Colville whispered to him before he died. With the help of Everyone, Holmes gets dental records and match them to vampire killer's bite. They find that Colville's teeth were the model for dentures issued at Newgate prison. After finding a good suspect, prison dental assistant Stan Kovic, he's cleared of the murders. Watson confronts Fleming again who admits that Colville whispered that he'd killed two women. Watson tells Holmes about Fleming's confession which leads him to believe the killer knew about the dentures and wanted to cast doubt Aaron was the killer. Holmes and Watson discover Aaron's mother Ruth is the killer and find a copy of Aaron's dentures at her house.
"No Lack of Void": Watson heads to the 11th Precinct where she's asked by Captain Gregson to look at a prisoner, Apollo Mercer, who has collapsed in a holding cell. She discovers Mercer has died from anthrax poisoning. Holmes reviews videos and tells Watson that Alistair died the week before of a heart attack. Gregson asks Watson and Bell to visit Eugene MacIntosh, brother of a suspect, Bart. Eugene indicates where Bart may be which Watson relates to Holmes. After seeing a case loaded into the truck, he breaks in and discovers the case is filled with jars of white powder. Two men surprise him and in the struggle, he subdues them, but they are all covered with the powder. Later at a hospital, Watson meets Holmes who is miffed he's being tested as the powder was baby powder. Watson is angry Holmes took such a big risk when a police team was minutes away from the truck. The next morning, Watson confronts Holmes that he lied to her about Alistair who died of a heroin overdose. After an outburst from Holmes, she presses why he lied. Initially, Holmes says it was to protect Alistair's privacy but he eventually admits that Alistair helped him when he was high, something most recovering addicts wouldn't do. After Bart kills his brother Eugene, seemingly in self-defense while claiming he was poisoning his cows with anthrax, Watson and Bell discover Bart poisoned his cows for an insurance payout while trying to pin the poisoning on Eugene.
"The Man With the Twisted Lip": Mycroft returns to NYC and asks Watson out to eat at Diogenes while Sherlock and Watson search for a missing woman, Paige Dahl. At Diogenes, Mycroft proposes dating Watson and while she's interested, she's worried it would makes things with Sherlock difficult. At a park, Watson finds Paige dead in the woods while Sherlock finds a dead man, Zach Piller, against a rock. Sherlock is puzzled by shotgun blasts on the rocks around Piller and, the appearance of a mosquito, though it's winter. At Piller's former workplace, Sherlock and Watson find Piller worked for a company that makes drones. At Diogenes, Sherlock tries to stop Mycroft from dating Watson and takes a picture of a man he noticed there before. As Sherlock shows her the photo of the man, de Soto, who is a lieutenant in a French crime organization, Le Milieu, Watson expresses her anger at him interfering in her relationship with Mycroft. Believing that Mycroft is involved with Le Milieu, Sherlock then bolts out of his chair, grabs a glass and captures something on a table. Hearing clinking, he explains to Watson that he's captured a tiny surveillance drone. He now knows why there was a strange shotgun pattern around Piller's body, he and Paige were killed by drones. At Diogenes, Watson expresses her interest in dating Mycroft but indicates that she'll have to move out of the Brownstone first. She also sees a man, Marchef, who was sitting at the same table when she met Mycroft earlier and she takes his picture. At the precinct, she now agrees that Le Milieu is using Diogenes as a base and shows Sherlock her picture of Marchef who is linked to a massacre. Watson break into the office of an executive of the company Piller worked for while Sherlock meets the executive. They are able to prove that the executive ordered Piller to carry out a drone strike in Afghanistan which killed CIA operatives, then covered it up and had Piller killed. Watson heads to Diogenes where she's kidnapped by Marchef.
"Paint It Black": Marchef informs Watson that Mycroft will be helping them or she will die. Watson hears screaming and discovers from Marchef that his cousin, Jem, has been shot. Since Marchef won't take him to the hospital, she offers her help. Having operated on Jem, Marchef warns Watson that if Mycroft fails, he'll still have to kill her. Watson tries to care for Jem who has gone into shock. Marchef tells her that it was Mycroft's idea to use Diogenes as Le Milieu's base. Having done everything she can for Jem, Watson tells Marchef he needs a hospital or he will die. To Watson's shock, Marchef shoots Jem in the head. His phone rings with news that Mycroft has succeeded and she'll be exchanged for the list. The exchange location is under an overpass where Mycroft alone meets de Soto, Marchef and a number of Le Milieu men. After providing the list and Yoder, de Soto orders Marchef to kill Mycroft and Watson and drives away. Unable to persuade Marchef to spare them, Mycroft is granted last words with Watson. He says "paint it black" and shots ring out killing Marchef and his men. Several black SUVs race onto the scene and British black ops soldiers secure the location. Mycroft tells Watson he has much to explain to her.
"Art in the Blood": At the Brownstone, finding guards and Watson being attended to by a doctor, a furious Sherlock turns on Mycroft and believes Mycroft is being arrested by British Intelligence only to be told that he works for them. Meeting Mycroft's handler Tim Sherrington, he debriefs Sherlock on the rescue of Mycroft and Watson from Le Milieu and that they needn't be worried about repercussions. To Mycroft's surprise, Sherrington asks Sherlock to work on a case of an ex-MI6 analyst, Arthur West, who has been murdered. Over Mycroft's objections, Sherlock agrees to look into West. Returning to the Brownstone, Sherlock discovers that Watson wants to work so he fills her in on West's case. At the Morgue, they discover that Arthur's arms are missing. Arthur's wife, Marion, eventually reveals she tattooed numbers on Arthur's arms in infrared ink and gives them a picture of the tattoos, which are all numbers. She doesn't know what the numbers mean and that Arthur was convinced there is a mole in MI6. He did say the mole was selling secrets to a bookstore owner, Julian Afkhami. Sherlock deduces that the data represents dates and times, but to what, he doesn't know. Watson tells Sherlock that she's moving out of the Brownstone which he thinks is a knee-jerk reaction to her kidnapping. Explaining that she's planned it for a while and that she needs a life outside of detective work, he's stunned into silence and then leaves. Watson goes to Mycroft's apartment and asks him to explain about a man named Sudomo Han. After Mycroft left MI6, Han employed Sherlock, at the height of drug use, as a courier of trade secrets. However, Sherlock didn't know he was aiding Han in financing a terrorist plot. The plot was thwarted but after Sherlock's involvement was discovered, MI6 pressured Mycroft into returning to work in exchange for Sherlock not going to jail. Sherlock knew nothing of this and realizing how much Mycroft sacrificed for Sherlock, Watson kisses him. In bed at Mycroft's, Watson tells him that she's moving out of the Brownstone and that Sherlock didn't take the news well. Sherlock calls Sherrington and says he knows who the mole is. Breaking into Mycroft's, Sherlock catches them in bed and tells Mycroft that he's being framed for murder and treason.
"The Grand Experiment": At a safe house, Sherlock believes a mole in MI6 is framing Mycroft. He's told MI6 what he knows but also said that Mycroft is the mole. He hopes this will gain MI6's confidence and while pretending to work with them to find Mycroft, that he'll find the real mole. Sherlock meets MI6 Deputy Chief, Sir James Walter and Mycroft's handler, Tim Sherrington, but is unsuccessful in gaining access to their files. He lies that he'll let them know when he finds Mycroft. Sherlock and Watson break into Julian Afkhami's store and Sherlock finds a scrambler that Afkhami could use for certain calls. Arthur West wouldn't have understood the calls but Sherlock believes he would know the date, time and location of them. At the safe house, Sherlock examines the info West had tattooed on his arms. Although burner phones would have been used by Afkhami's contact, the code of the cell tower used would be part of the metadata of the call. Sherlock realizes this is what West tattooed on his arms. As he reads the locations and dates, Mycroft confirms that he was at locations. Watson deduces that Sherrington was also there and that he is the mole. Sherlock finds that the dates correspond to events that benefited Iran and that Sherrington provided secret information to make the events occur. While Sherlock is called to the precinct, Sherrington visits Watson at the Brownstone and threatens her. However, she's prepared for this and has various members of Everyone witness Sherrington's threatens via monitors in the the media room. At the safe house, Sherlock wakes Mycroft to tell him about Watson's encounter with Sherrington and, that he knows why he re-joined MI6. He's confused why Mycroft would make such a sacrifice when he owed Sherlock nothing but Mycroft simply states they are brothers. Sherlock vows to fix the Sherrington situation. After Sherlock and Watson find evidence that Afkhami killed a man who was having an affair with his wife, Gregson tells Sherlock that Afkhami gave Sherrington up. Sherrington turns up dead and Gregson tells Bell to put out a Finest Message for Mycroft. At the Brownstone, Sherlock and Watson confront Mycroft who says he didn't murder Sherrington. He contacted NSA Agent McNally who he traded MI6 secrets for the NSA arranging for Sherrington's murder. Sherlock deduces that the NSA has faked Mycroft's death which he confirms. Mycroft will have to disappear which he tries to apologize to Watson for. She leaves, frustrated and upset. Sherlock indicates that they were working on a solution for him that would take hard work which isn't Mycroft's way. Mycroft interrupts Sherlock's chastisement by hugging him, proclaiming his love, and then leaves. Eavesdropping outside Watson's bedroom, Sherlock hears her making an appointment to view an apartment. Distressed, he retrieves a hidden stash of heroin. He then visits Sir Walter and agrees to work for MI6.

Season 3[]

You know how much I value you. I've made that clear on numerous occasions, sometimes embarrassingly so. You've been a good friend and a good partner.

— Holmes, "Seed Money"
S03E01-Watson single stick

Joan Watson Season Three/Gallery

While Watson battles drug lord Elana March, Holmes returns to NYC with a protégée, Kitty, but must gain Watson's approval to work at the 11th Precinct again. Residing in an apartment, she meets a neighbor, Andrew Mittal, who becomes her boyfriend. Watson assists Kitty's development and has her attend a support group meeting for victims of trauma. Watson accompanies Andrew to Denmark as he meets with a new business partner. With the help of Ms. Hudson and The Nose, a mystery involving missing persons where their abduction scenes smell like nutmeg is solved. Watson is tempted by an ex-boyfriend, Chris Santos. Watson and Holmes pursue a viscous cop-killer, set on robbing the NYPD's armory.

Appearances in Season 3
"Enough Nemesis To Go Around": Watson meets drug lord Elana March for a tense lunch. March cattily denies being a criminal and taunts Watson, saying that she's wasted six month trying to convict her. However, Watson has found March's bookkeeper and invited March to lunch so that her bodyguards would be occupied. Police have arrested the bookkeeper who has given the police enough information to convict March. Captain Gregson arrives and takes March away. Days later at Watson's apartment, a client meets her in her home office when Detective Bell calls. He asks her to join him and the bookkeeper, Karen Lloyd, who wants to review the courthouse security again before she testifies against March. On her way out, Watson encounters new neighbor Andrew Mittal and helps him find a lost lizard. Watson meets Lloyd and reassures her she's safe as Lloyd enters the hotel elevator for court. Lloyd and Detective Palmer are found shot dead in the elevator. Two months later at the 11th Precinct, Bell and Watson are still puzzled by the elevator shooting. The elevator didn't stop, no one entered and the bullets wounds reveal the shots were horizontal. With March free, a tip that a hotel guest, Kevin Elspeth, is the murderer leads Watson to the Brownstone where she discovers Holmes has returned and provided the tip. Holmes admits that he should have said goodbye properly but Watson is still bitter and says she doesn't need his help. After Bell and Watson question Elspeth, who denies murdering the bookkeeper. Outside, Watson notices she's being followed by a woman, surprises her and pulls out her single-stick. The woman smiles, pulls out one of her own and they battle. Watson wins and the woman says she's Holmes' new partner. In the hotel where Lloyd was murdered, Watson goes to use the elevator and finds Holmes inside, tracing the bullet shots. Annoyed that he isn't staying out of her case, he follows her to the hotel room Elspeth stayed in when Lloyd was killed. To gain her sympathy, he admits that he left NYC for London because he was afraid that with Watson moving out of the Brownstone, he might relapse. Largely ignoring him, Watson proceeds into the bathroom. Holmes notes it is beside the elevator Lloyd was killed in and, the bullet were shot towards his room. Holmes sits on the bench in the shower and reminds Watson that she should examine a crime scene from all perspectives, but she's too angry to take the hint. At the Brownstone, Watson warily greets Kitty who indicates that Holmes has solved her case. With a model, Holmes shows Watson that Elspeth jammed four steel slugs in the side of the elevator and then positioned a large magnet in his hotel room bathroom. He monitored Lloyd's protective detail's radio messages and once she was in the elevator, pulled the magnet's switch. The steel slugs were pulled through the elevator, killing Lloyd and Palmer. Later, Watson finds proof that Holmes' theory is correct, resulting in Elspeth and March's arrests. Watson arrives at the Brownstone to let Holmes know about March's arrest which he congratulates her on. She's also signed off on Holmes and Kitty working with the NYPD but insists that they work their own cases. Outside the Brownstone, Kitty catches Watson and expresses her gratitude for allowing her to work with the NYPD.
"The Five Orange Pipz": The murders of Elias Openshaw and his attorney, Theo Fordham, result in Watson allowing Holmes to join the case. Beads found at both men's murder scenes or "the Pipz", were made by Openshaw's company and when ingested, metabolized into GHB. A hallucinogen used as a "date rape" drug, nine children had been killed or poisoned by swallowing the Pipz. Meeting Gregson in his office, they're introduced to FBI Agent Vince Boden who indicates the FBI had proof Openshaw knew the Pipz were poison but sold them anyway. The FBI seized all of the Pipz and Boden has no suspects other than a list of the parents of the children who'd been poisoned. Holmes texts Watson to join him at the office of US Attorney Angela White, the prosecutor of the Pipz case. She denies Holmes' request for access to surveillance video of Theo, citing privacy concerns, and Kitty accuses her of not wanting them to find the real killer. Offended, White ends the meeting. Questioning Boden at his home, he denies knowing about an encounter between White and Openshaw but says that White had motive to kill Openshaw and Theo. White admits to the missing evidence, blackmail and agreeing to Openshaw skipping bail. However, she denies committing the murders. Holmes takes Watson to his bedroom and removing bricks in the fireplace, takes out a file on Kitty and gives it to Watson. He explains that Kitty was the victim of a horrific crime and was taken by a man who is still at large. Watson comments that Kitty had a good point about Boden which makes Holmes realize that perhaps Boden was trying to end the proceedings against Openshaw. Gregson and an ESU team catch Boden leaving a waste facility in a truck filled with boxes of the Pipz. Holmes compliments Kitty on the points she made that helped with the solving of the case. Later at the precinct, Watson sees Kitty going through old cases Holmes and Watson worked on. She gives Kitty the file Holmes gave her and indicates she never read it. Kitty insists that Watson read it to get a better sense of her.
"Just a Regular Irregular": Watson asks Kitty for help following a real estate investor, Chad Keswick. Watson has been hired to find out why he is interested in a building. At Watson's apartment, Kitty shows Watson surveillance pictures of Keswick. Watson says she read Kitty's file on her rape and abuse but Kitty doesn't want to discuss it. At Watson's apartment, Holmes has an uncomfortable first meeting with her now boyfriend, Andrew. After Andrew leaves, Watson advises Holmes to get Kitty help dealing with her past. While investigating a murderous math game Harlan Emple is involved with, Emple, Holmes and Watson meet on the players, Paul Ettinger, who believes a blogger, "Mo Shellshocker" is the killer. In private, Emple admits he is "Mo" and explaining that he was fighting those that abuse math. At the Brownstone, Watson tells Kitty that Keswick's interest in the building was due to a valuable mural that was painted over in the lobby. Kitty indicates she's going to a support group meeting and knows Watson put Holmes up to insisting she go to one. Kitty asks for Watson's on-going help as she works through her issues.
"Bella": Holmes takes on a case from Edwin Borstein who claims a stolen artificial intelligence program named "Bella" is sentient. Tasking Kitty and Watson to find the thief, Watson finds that Holmes has involved him in an on-line discussion on Bella. Watson is somewhat taken aback but says it's fine for him to help. Borstein is found dead, seemingly killed by Bella using a program that induced an epileptic seizure. Andrew tells Watson that as a result of participating in the discussion on Bella, he found a new business partner in Denmark and will be leaving in a few days. Watson accuses Holmes of meddling in Andrew's life. Holmes convinces Watson that he likes Andrew and has no desire to interfere in Watson's relationship with him.
"Terra Pericolosa": Holmes send Kitty to a library where she finds a security guard dead in a display case. Holmes deduces that a map, "The County of King James, Virginia, 1794" which was loaned to the library by the Bray family, was the target of theft. Visiting Margaret Bray at her charity's office, she agrees to help find other institutions who may have had thefts that went unreported. Holmes finds the map thief, Stuart Zupko, dead in his at his shop with all the stolen maps including the Bray map which is laid out. However, Holmes sees the Bray map is a fake. Discovering Kitty has a suitor, Holmes tries to keep her busy with trivial tasks. Holmes and Watson meet real estate tycoon William Hull, Hull is also interested in finding the Bray map and offers to hire them but Holmes walks out. He realizes the map itself isn't what is of interest, but the information on the original map. The next morning Holmes wakes Watson and shows her that the forged map and the original are identical. However, a river in the map has shifted its course over the last 200 years. A casino is planned for construction on a site on an Indian reservation, which due to the shifting of the river, is actually not on the reservation. Existence of the original map would spell the end of the casino project, costing billions. At the casino manager's office, Watson realizes who is behind the library theft and murder. At the precinct, Margaret is shown evidence she committed the murders and map theft in order for the casino to be built on land her family owned.
"The Adventure of the Nutmeg Concoction": While involved in a case concerning bodies at crime scenes which are dissolved using a nutmeg concoction and The Nose, on her way to her apartment, Watson runs into Chris Santos who she knew from her time as a doctor. Santos asks for her help finding his stolen medical ID. Watson has Kitty look into the matter and Holmes deduces that Chris was a lover of Watson's. She reveals they dated for two years and he bought her an engagement ring. After Kitty finds who stole Chris' ID, Watson meets Santos at a coffee shop and shows him the identity of the thief. Chris compliments Watson and mentions that he should have been more accepting of her tendencies when they were together. Later, receiving a text from Santos asking her out on a date, Holmes asks Watson if she mentioned to him that she is dating Andrew. Admitting she didn't, Holmes believes that she's torn between having a conventional relationship, which she'll always sabotage, and seeking adventure. Watson turns down Chris' offer.
"End of Watch": After Officer Alec Flynn is killed, Watson notices fibers in a boot print left by the killer and Holmes discovers that Flynn's gun is an air pistol. Flynn's wife Brie admits to Detective Bell and Watson that after a football accident, Alec became addicted to Oxy. However, he recently became sober, came back home and was proud to return to active duty and leave working at the armory. Discovering Flynn sold his pistol and those at the armory to criminal Niko Buros, his inspector's funeral is cancelled. That evening, Buros kills another officer, Casey Hatem, and more fibers like the ones found at Flynn's murder scene are found. Watson discovers Charlie Riggs supplied Alec with Oxy and introduced him to Buros. From his testimony, Holmes realizes Buros shot both Flynn and then Hatem in order for an inspector's funeral to be held in which the armory would be barely manned in order to rob it of its weapons. However, Buros successfully robs the armory. From one of Buros' weapons stashes that was seized, Watson deduces that Buros was hiding the guns in furniture which were then transported to Mexico. Holmes deduces that Buros was on a strict timetable for sending the weapons which points to use of a cargo ship bound for Veracruz. Buros is found by Bell and an ESU team and arrested.
"The Eternity Injection": A nurse, Shauna Milius, arrives looking to hire Watson. Milius reports that a fellow nurse, Marissa Ledbetter, disappeared and police haven't been able to find her. Holmes finds Marissa's body and that she died of head trauma and strangulation and, has DNA under her nails that matches a Chris Jacoby. Mason finds Chris was in a park using city surveillance footage and facial recognition software. Chris is found dead in the woods and Holmes discovers a journal hidden under a rock. Holmes finds that Chris received a $150,000 payment from the same company as Marissa, Purgatorium. Dr. Hawes finds Chris' brain was destroyed and an unidentified chemical found in his system. Holmes believes that Chris was part of an illegal drug trial that Marissa was the nurse on. The list found on Marissa showed five dosages, indicating that four other people were given the drug, EZM-77, and are being murdered to cover up the drug trial. Everyone provides a list of those that received payments from Purgatorium. Holmes and Watson find one of the drug trial members, Louis Carisle, who identifies Dr. Dwyer Kirke as the leader of the trial. Having found who funded Kirke's research, Holmes and Watson are shown into the palatial home of James Connaughton by his nurse Brett Won. Having been diagnosed with a terminal disease, Holmes cannot motivate James to admit guilt and he has his nurse take him to bed. Watson suggests that Won be brought to the precinct where the scale of the trial is made known to him. He reveals that he saw a contract for Purgatorium in James' safe and that two hitmen visited James who gave them the list of the participants. Accompanying Bell and police for James' arrest, Holmes and Watson find him in bed having taken a dose of EZM-77. His eyes twitching rapidly, James cannot be woken and Holmes speculates that he took the drug to experience as much time as possible in his remaining days.
"Seed Money": At the scene of the death of an elderly couple, Watson speculates they committed suicide but Holmes leads her and Bell into the building's basement where a burned body is found. Checking the third floor, the body is found to be Clay Dubrovensky, who had a doctorate in botany and genetic engineering. Holmes says that Clay's burning death, necklacing, is a trademark of a Brazilan gang, SDS. The next morning after breaking into Watson's apartment, Holmes wakes Watson by making her a smoothie with a blender. From some Russian coins found at Clay's, he's been able to identify the neighborhood the grow house is in. Watson tells Holmes that she's folding her private detective business and will be working for insurance company Leda as an in-house investigator. Meeting Captain Gregson at the grow house, they are puzzled to discover most of the pot plants are dead. Holmes spots a valuable, one-of-a-kind orchid, the Wutai Pingtung, on a shelf and believes Clay may have been killed over it. Barbara Conway, a senior VP at AgriNext is questioned by Bell, Holmes and Watson at her company's office. Having found that she bought a cabinet that had the orchid on it, she denies knowing Clay. Told they believe she killed Clay when he didn't deliver the orchid, she insists it was thrown in for free, the seller was anonymous and gives them the second orchid. Conway provided two bags of plant food and as Watson opens one filled with ground coffee and dried fish, Holmes tells her that's the wrong one for orchids. After Conway reveals that AgriNext was negotiating for Clay's release from the SDS in order to grow pot for them, Watson reviews AgriNext memos that proves this. In order to stimulate thought, Holmes opens the plant food bag with coffee and fish and the strong odor fills the room. Holmes tells Watson that he's decided to make Kitty his new partner. Watson meets an ex of Clay's who has plant food that smells of coffee and fish. Watson meets Conway alone and says she knows that she and Clay were lovers. After Conway discovered Clay was also sleeping with an ex, she confronted him and in anger, killed him with a blow to the head. She then tried to frame the SDS by burning him. Conway breaks down and confesses, saying that she loved Clay and kept a flower he'd given her. Watson calls Holmes and informs him of Conway's confession while he indicates that he's about to tell Kitty about her promotion. However, a call from Gregson interrupts asking for Holmes alone to come to a crime scene.
"The Illustrious Client":

Season 4[]

When it comes to what we do, the only thing that matters to me is our partnership, so you go, I go.

— Watson to Sherlock, "The Past Is Parent"
S04E11-Watson boxes

Joan Watson Season Four/Gallery

After assaulting Oscar Rankin, Sherlock expects to be jailed and convinces Watson to work on a last case involving Jonathan Bloom.

Appearances in Season 4
"The Past Is Parent":

Season 5[]

I'm better at the work I do because of you. But over the years the relative importance of those two values has flipped. I now value the work that we do, first and foremost, because I do it with you.

— Holmes to Watson, "Henny Penny the Sky Is Falling"
S05E15-Watson and Archie long

Joan Watson Season Five/Gallery

Watson commits to helping a former patient and ex-con, Shinwell Johnson.

Appearances in Season 5
"Folie a Deux":
"Worth Several Cities":

Season 6[]

Everything she saw in you that matters, all your best qualities, they're not the things that would make you a great mother, they're the things that do make you a great detective. A great friend. A great sister.

S06E20-Watson w rotor

Joan Watson Season Six/Gallery

Watson deals with Holmes' post-concussion syndrome and the death of her biological father.

Appearances in Season 6
"An Infinite Capacity for Taking Pains":

Season 7[]

S07E05-Watson red dress

Joan Watson Season Seven/Gallery

While working on a case in London with Scotland Yard, Holmes and Watson learn from Detective Bell that Captain Gregson has been shot.

Appearances in Season 7
"The Further Adventures":


High intellect[]

Watson has sufficient intelligence to gain the respect of Sherlock Holmes, as well as become the valedictorian of a med school. She is also trained in deductive reasoning, and a wide knowledge of facts to help in her investigations by Holmes.


Watson is a highly trained physician and surgeon, with all the attendant knowledge.


Watson speaks Mandarin Chinese, though not with complete fluency.


Watson has been trained by Holmes to be at least proficient in using single stick in combat.

Hand-to-hand combat[]

Watson has been trained by Holmes in unarmed combat, with sufficient skill to defeat an experienced police detective in a match.


Watson is sufficiently skilled to pick most locks in seconds


Watson is a talented pick pocket, having gained at least basic proficiency in a matter of a few days.


Watson has been trained in escapology by Holmes, able to get out of handcuffs and similar restraints within short periods of time.


Watson has been trained in the art of observation and reading people by Holmes


Sherlock Holmes[]

S03E09-Watson Holmes bugle

"Cold feet on the warm deck Watson!"

At first, Sherlock was simply an annoying client for Watson. However, as time passed, their shared experiences made them friends, and in time, the two came to love each other.

A running gag on the show, Holmes often wakes Watson in amusing ways. Occasionally, Watson returns the favor.

Ty Morstan[]

S01E02-Ty and Watson

"So he's your boyfriend?"

Ty Morstan is an ex-boyfriend of Watson's and works in the district attorney's office. Ty has dinner with Watson during her first weeks as Holmes' sober companion. He tries to find out about Watson's latest companion and indicates that he and her parents are worried about her. Watson doesn't appreciate their concern. Later, as Holmes and Watson pull up to the Brownstone in a taxi, Ty is waiting on the steps with a bottle of wine. Holmes admits he hacked Watson's phone and invited Ty to a fake dinner party, obviously to learn more about her. Watson is mortified and explains the situation to Ty who is not impressed as he turned down drinks with the district attorney. Watson leads him away and Ty says Holmes is lucky he didn't slug him for the prank.[3]

Liam Danow[]

S01E09-Watson and Liam

"We've had this conversation before."

Liam Danow is a drug addict who was Watson's ex-boyfriend. She met him when she was a doctor, they became lovers and he turned to drugs later. She unsuccessfully tried to help him but learned much about being a sober companion in the process. At Rikers Prison, Watson meets Danow, who's been arrested for a hit-and-run that he swears someone else committed with his car. He admits that he was high that night, but would have remembered. He asks Watson to help with her friend at the D.A.'s office, but she refuses. As she leaves, he asks if she treats all her ex-lovers this badly. Watson shows Liam the crime scene photos of his car. He apologizes for his unkind words and she asks him why he keeps repeating his past mistakes and using drugs. Liam notices that the keychain Watson gave him is gone. Later, Watson shows Liam a news article in which his car thief has been arrested which clears him of the hit-and-run. Liam is grateful, but Watson says she won't bail him out anymore. She's made an appointment at a rehab clinic and leaves it with him.[4]

Mycroft Holmes[]

S02E01-Mycroft meets Watson

"I'm Sherlock's brother."

Sherlock's older brother, Watson meets Mycroft in London at 221B Baker St. in 2013. Surprised that she's become Sherlock's friend, he invites her to dinner to learn how to repair his relationship with Sherlock.[5] Months later, Mycroft visits NYC to develop a restaurant, Diogenes. At his request, Sherlock and Watson help Nigella Mason and Sherlock learns that Mycroft and Watson slept together when in London.[6] Mycroft returns months later to open Diogenes and tells Watson he'd like to pursue a relationship with her. Watson is kidnapped by a Diogenes patron, Marchef, a member of the French gang "Le Milieu."[7]

S02E23-Watson and Mycroft

"That was all to protect Sherlock."

Mycroft is able to rescue Watson, who witnesses the shooting of her kidnappers and learns Mycroft works for MI6.[8] Shocked, Watson vows to never see Mycroft again but when she learns that he made an incredible sacrifice for Sherlock, she sleeps with him.[9] In order to protect Sherlock and Watson from a mole in MI6 and "Le Milieu" survivors, Mycroft fakes his own death. He departs and Watson never sees him again.[10] She learns he died in 2017.[11]

Andrew Mittal[]

Andrew paek s03e03

"I swear I usually wear pants."

Watson meets Andrew, a software engineer, when he was living in his brother's apartment near to Watson's apartment. He misplaced his brother's lizard which Watson helped him find. He asks how he can repay her and she gives him her business card and leaves for a meeting.[12] Andrew meets Holmes at Watson's as he is coming out of the bathroom with no pants on. Holmes comments that Watson appears adequately sexed by him.[13]

S03E13-Santhosh Watson Andrew

When investigating an AI case, Holmes asks for Andrew's help which puts him in contact with many intelligent people with computer skills. Watson thinks Holmes is trying to find out about Andrew but he claims innocence. This puts Andrew in contact with a future business partner that requires him to spend significant time in Denmark, much to Watson's disappointment. However, she surprises him by flying to Denmark with him to spend the first few days of his trip there with him.[14] When Andrew returns from Denmark, Watson has dinner with Andrew and his father, Santhosh, which goes perfectly but makes her realize that she doesn't want a conventional relationship. Days later, she invites Andrew to a coffee shop to break up with him. Andrew drinks a latte, meant for Watson, that was poisoned with hemlock by an assassin hired by Elana Marsh and dies.[15]

Chris Santos[]

S03E07-Watson Santos

"I cringe when I think about how immature I was."

On her way to her apartment, Watson runs into Chris Santos who she knew from her time as a doctor. Santos asks for her help finding his stolen medical ID. Watson has Kitty look into the matter and Holmes deduces that Chris was a lover of Watson's. She reveals they dated for two years and he bought her an engagement ring. After Kitty finds who stole Chris' ID, Watson meets Santos at a coffee shop and shows him the identity of the thief. Chris compliments Watson and mentions that he should have been more accepting of her tendencies when they were together. Later, receiving a text from Santos asking her out on a date, Holmes asks Watson if she mentioned to him that she is dating Andrew Mittal. Admitting she didn't, Holmes believes that she's torn between having a conventional relationship, which she'll always sabotage, and seeking adventure. Watson turns down Chris' offer.[16]

Family tree[]

Jin May Wen
Mary Watson
Henry Watson
Henry Watson
Lin Wen
Lin Wen
Joan Watson
Oren Watson


  • She is a New York Mets fan.[17]
  • She lived a few blocks away from Cobble Hill in the mid-2000s.[1]
  • Zadie Smith is one of her favorite authors.[18]
  • Her biological father is schizophrenic and homeless. She occasionally volunteers at a homeless shelter to help people and to see her father.[19]
  • She owns an iPhone[17] and a Blackberry.[20]
  • Her brother being named Oren is an homage to Lucy Liu's character in Kill Bill, O-Ren Ishii.[21]
  • Her mother, Mary Watson, is a reference to John Watson's wife, Mary Watson (née Morstan) in Sir Arthur Conan Doyle's Sherlock Holmes stories. Joan also had an ex-boyfriend named Ty Morstan.
  • She lived on Ogden Avenue as a child and had a dog named Grover.[22]
  • She understands and speaks Mandarin Chinese.[23][24]
  • She worked at Corona General Hospital in Queens in the 2000s.[25]
  • She appears in every episode in Elementary except for "Rip Off."
  • See also Dr. Watson on Wikipedia, whom Elementary's Joan Watson is based on.
  • During Season 1 she sometimes reads wearing glasses.


One way or the other, I'm going to be out of your life in a few weeks. Maybe you're dreading that day. Maybe you're counting the seconds. Either way, I'm going to make sure you're ready when the time comes. I promise.

— Watson to Holmes, "The Long Fuse"

And you even made a friend, something that Kathryn claimed in her article was virtually impossible. Me. I'm talking about me.

— Watson, "The Deductionist"

Why are you poking me with your single stick?

— Watson, "The Marchioness"

I don't care which cock I'm holding, I just want to know how it got there. Okay, congratulations. You got me to say it.

— Watson, "The One Percent Solution"


  1. 1.0 1.1 Season 1, episode 3: "Child Predator"
  2. Season 1, episode 5: "Lesser Evils"
  3. Season 1, episode 2: "While You Were Sleeping"
  4. Season 1, episode 9: "You Do It to Yourself"
  5. Season 2, episode 1: "Step Nine"
  6. Season 2, episode 7: "The Marchioness"
  7. Season 2, episode 21: "The Man With the Twisted Lip"
  8. Season 2, episode 22: "Paint It Black"
  9. Season 2, episode 23: "Art in the Blood"
  10. Season 2, episode 24: "The Grand Experiment"
  11. Season 6, episode 9: "Nobody Lives Forever"
  12. Season 3, episode 1: "Enough Nemesis To Go Around"
  13. Season 3, episode 3: "Just a Regular Irregular"
  14. Season 3, episode 4: "Bella"
  15. Season 3, episode 13: "Hemlock"
  16. Season 3, episode 7: "The Adventure of the Nutmeg Concoction"
  17. 17.0 17.1 Season 1, episode 1: "Pilot"
  18. Season 1, episode 6: "Flight Risk"
  19. Season 2, episode 15: "Corpse de Ballet"
  20. Season 1, episode 7: "One Way to Get Off"
  21. Elementary Writers (@ELEMENTARStaff). "Inadvertent homage to Lucy's character in Kill Bill, O-Ren Ishii?!" December 14, 2012.
  22. Season 4, episode 7: "Miss Taken"
  23. Season 4, episode 14: "Who Is That Masked Man?"
  24. Season 5, episode 14: "Rekt in Real Life"
  25. Season 5, episode 10: "Pick Your Poison"