Our work, what we do, it's not just a job now. It's who I am. I'm a detective. I'm ready to embrace that.
Meeting Elana March in prison, Watson recounts the events that led to her boyfriend Andrew Mittal's poisoning. Accusing March of hiring the poisoner, she denies it but warns Watson that anyone involved with her will be in danger. March also says she heard that Watson was breaking up with Andrew just before he died. At the 11th Precinct, Captain Gregson tells Watson he'll post a unit outside her apartment but Watson believes March will wait a while before ordering another attack on her. She tells Holmes that she'll need a few more days before resuming casework. At The Brownstone, Holmes meets with Vernon Joseph who knows Holmes from a beekeeping message board he operates. After making several concessions to Holmes, he takes him to the Bronx zoo, where he is a curator, and shows Holmes that two pregnant zebras have been stolen.
They're due in less than a week.
On forced vacation, Detective Bell meets Holmes at the zoo and agrees to work with him on the case. Examining the scene, Bell is miffed why Holmes won't call him by his first name. Tire tracks are found and Bell notices a distinct purple paint scraping on a metal gate which Holmes recognizes is used by the trucks of a delivery company, APD. At the Brownstone, Holmes has discovered from APD that one of their trucks was stolen eight days before and he's obtained the truck's manifest. From a pet collar with a GPS chip that the truck was carrying, he and Bell find the truck's load which has been dumped under an overpass. Shifting through the load, Bell gives Holmes advice on how to handle the stress Watson is experiencing. Holmes finds a receipt from a horse veterinary service and they proceed to its address.
How is this supposed to help us?
At Watson's apartment, Andrew's father Santhosh Mittal returns some of Watson's items that were at Andrew's. With sadness, he indicates that he doesn't blame her for Andrew's death, but wishes she'd done more to protect him. The vet service is located near a warehouse where Bell discovers the APD truck abandoned, with hay in the storage area. They find the two zebras, who have both given birth, but their offspring aren't there. Digging through a hay pile, Holmes finds a veterinarian, Dr. Chang, dead from a gunshot. Later with police on the scene, Bell reports that Chang had skin under his fingernails, likely from his killer. Bell believes Chang was part of the theft but Holmes shows evidence that he was not and that the APD truck had a broken axle, explaining why it was abandoned. From broken glass on the street, he deduces that an SUV was used to transport the zebra foals and, in the zebra droppings, he finds the name of the company where the hay was purchased, "Federal Feeds".
Both of these animals have given birth.
Later at Watson's apartment, Holmes brings her lasagna and Watson indicates it's OK for him to work. Explaining that she moved out of the Brownstone as she wanted a life away from detective work, she now realizes that keeping their work and her private life separate isn't possible. In the morning, Holmes has fallen asleep on a desk and with satisfaction, Watson wakes Holmes by slamming a book next to his head. Explaining the case he's working on, the manager at Federal Feeds described the man who bought the hay and said he complained about a hailstorm. Though police have searched all barns in the hailstorm area without finding the zebra foals, Watson uses a map and points to an abandoned psychiatric hospital that had a working farm with stables. With a police team, Bell and Holmes search the hospital and one of the foals is found. However, Holmes points out that the foal isn't a zebra, but a quagga, which have been extinct since 1883.
It's an equine species native to South Africa.
At the precinct, Holmes and Bell report their findings to an astounded Vernon Joseph. Pointing out that de-extincting a quagga would take a lot of care of the pregnant zebras, and that the person who did it intends to sell the quaggas on the black market. They ask for Joseph's help after establishing his whereabouts the previous day. At the zoo, Joseph has gathered all the staff who work with the zebras. After thanking Holmes and Bell, Holmes explains that the zebra thief and killer of Dr. Chang is among the staff and to Bell's astonishment, accuses an African-American man. Bell pulls Holmes aside who explains that he's found the real killer among the staff, Ben Reynolds, by observing the change in his body language since the false accusation. In "the box" at the precinct, Reynolds, a PhD candidate in zoology, won't co-operate nor provide his DNA.
One of you is being quite hypocritical.
Holmes arrives at Watson's apartment with her mail and news that a zoo employee provided a sample of Reynold's DNA from a soda can and, it matches the DNA found under Dr. Chang's fingernails. Watson finds a threatening postcard in her mail that appears to be from March. Bell calls that Reynolds has disappeared from his basement apartment even though police saw him enter and had it under surveillance. At Reynold's, Holmes examines the apartment and while telling Bell how the origin of the phrase "to 86" something came to be, he finds a tunnel through which Reynolds escaped. That evening at the Brownstone, knowing that Reynolds must sell the quagga soon to finance his escape, Holmes gives Bell all case files on the sale of rare animals and proposes they look for an on-line code that would indicate such a sale.
Out of the back door, the 86 Bedford Street door.
The next morning, Holmes wakes Bell using an alarm clock and Bell finds a note from Holmes telling him to meet at a café in Greenpoint. At the café, Bell sits with Holmes who has ordered him breakfast and explains it affords them the best vantage point for seeing Reynolds. Explaining that the phrase "once in a blue moon" was used on a web site to indicate an illegal animal sale, Holmes found Reynold's ad for the quagga, won the bid, arranged to meet Reynolds and called Gregson. While explaining, Bell sees Reynolds pull up in an SUV and meet a man who after seeing the quagga in the SUV back, waves his hat. Police descend on Reynolds and arrest him. Bell smiles at Holmes who shakes his hand and finally calls him "Marcus." Watson receives a letter from Moriarty expressing her regret at Andrew's murder and that attempts on Watson's life will be dealt with. Watson learns that Elana March has been killed in prison. She brings the news to Holmes at the Brownstone and indicates she's ready to dedicate her life to being a detective and wants to move back to the Brownstone.
Uninvited participants are not welcome at the table.
Holmes mentions he used the alias Sigerson to entrap Ben Reynolds which is a reference to Conan Doyle's The Adventure of the Empty House in which Holmes travels in disguise as a Norwegian explorer and uses this name.
"No, the pleasure was mine and mine alone Marcus."