Season: Four — Episode: 7 Director: Guy Ferland — Writer: Tamara Jaron — Aired: January 7, 2016 — Viewers (millions): 6.71 Summary: The duo goes against a clever opponent, who forces Holmes to think out of the box. Meanwhile Watson's troubles with her father are brought into focus when he writes a book about her and Holmes.
Sherlock and I do not run around with guns and we don't get into kung fu fights with criminals and we sure as hell do not sleep together.
— Joan to Henry
At the 11th Precinct, Captain Gregson calls Joan into his office and shows her a fictional book that is written about her and Holmes, with many artistic liberties. At a construction site, workers find a body has been put through a wood chipper and an FBI badge. At the Morgue, the remains are identified as retired FBI Agent Robert Underhill. Incapacitated by pepper spray, Holmes speculates the Agent was lured to the site by his killer. Underhill's wife Sheila is questioned at the precinct but has an alibi. She indicates they were separated and though retired, he was looking into old cases and told her he was close to cracking one. Having discovered her step-father is the author of the book, Joan confronts Henry at his house. She's bought all hard copies she could find and he doesn't understand why she's so angry. After she demands that no more copies be published, she tells him Holmes doesn't know about the book.
That is how you make a porn name, not a pen name!
At The Brownstone, Joan finds Holmes has lined rooms with three case files Bob Underwood had in his home. Holmes has solved all three and believes none resulted in Underwood's death. However, he found that Underwood requested the case file of Mina Davenport. Mina was kidnapped at age 8, escaped and returned ten years later. Her kidnapper was never found and Holmes finds it suspicious that her file was missing from Underwood's home. At the Davenport's, Richard and Nancy speak highly of Underhill, who worked Mina's case. Richard feels responsible for Mina's disappearance and they mention how it's taken years for her to feel safe. A shy Mina meets Bell, Holmes and Joan and outside their house, Holmes says that they've met an imposter of Mina. At the precinct, Gregson is shown a picture of Mina at age 4 and the imposter. Their ears are different shapes and Joan points out that ears don't change shape as people grow.
Has she remembered any other details?
Gregson mentions that DNA from four year old Mina's toothbrush matched DNA from the imposter. Even though the toothbrush disappeared after the test, Gregson finds it hard to believe that the Davenports wouldn't recognize their daughter. He's convinced to share their concerns with the Davenports, bring them to the precinct and collect DNA samples from them to compare to the imposter. The Davenports arrive but surprisingly, the imposter comes as well who says she wants to help. While Richard and Nancy go to Gregson's office, Holmes takes "Mina" into a conference room where she tells him about her abductor, a trucker named Keith. Describing a life of isolation in a basement and back of a truck cab where she had no access to any media, her escape was prompted by Keith's declaration they should start a family. While on a trip, she took a straight razor, ran all night, entered a gas station bathroom and shaved her head. Holmes doesn't believe her.
You are one of the best liars I have ever met.
"Mina" looks at Holmes with surprise and hurt while the upset Davenports, having heard the suspicions, burst into the conference room and whisk Mina away, demanding they be left alone. At the Brownstone, Joan relates that the Davenports refused to give their DNA while Holmes deduces that Joan visited Henry about the book. She's surprised that Holmes isn't angry about the book while he's puzzled why she is. The doorbell rings and they're surprised to find the imposter at the door, alone. She admits she's not Mina and claims that the Davenports killed both Mina and Underwood. In the library, she says her real name is Cassie, that in a few weeks she'll turn 21 and have access to Mina's trust worth $5M. In exchange for keeping her secret, she offers to spy on the Davenports in order to provide incriminating evidence. She relates that the Davenports helped her learn Mina's past and, that she saw Richard and Underwood arguing just before his murder.
My favorite wrinkle was Keith's truck.
Joan is surprised when Holmes agrees to Cassie's deal and he provides her with two listening devices. He asks Cassie to put one on each floor of the house near a window. After Cassie leaves, Joan comments how Holmes acted as if he believed her story while he informs her that one of the devices is a flash bang. When it explodes, they'll gain access to collect the Davenport's DNA and, search for traces of Agent Underwood. Later after the explosion, with the fire department at the Underwoods, Richard protests to having Holmes and Joan at the scene. Bell and Gregson don't know about the flash bang and leave Holmes and Joan alone in the garage while they search the house. While examining the vehicles, Joan tells Holmes she's angry about Henry's book because she hasn't forgiven him for his affair and felt that him writing the book was another selfish act. Holmes finds blood under the brake pedal of an SUV that he deduces Cassie drove.
I thought you said it was a small bomb.
Henry arrives at the Brownstone and gives Joan a draft of a sequel about her and Holmes to do with as she pleases. He confesses he wrote the books to feel closer to her as he knows that the affair pushed her away. Holmes calls Joan to report that the blood under the brake pedal was Underwood's and, Richard turned himself in and confessed to his murder. At the precinct, Holmes watches Richard's interrogation and suspects that Cassie played upon his guilt. However, with Richard in custody, he'll have to provide his DNA which Holmes is sure will prove is not a familial match for Cassie. Later in Gregson's office, they're astonished to find that Richard's DNA is a familial match for Cassie. Holmes notes that a cheek swab from Richard was compared to the shaved hair from the scene where Cassie was found. While Bell theorizes that Cassie is Richard's daughter from an affair, Holmes says he has a better theory.
In 2004, he couldn't save her. In 2015, he can.
Nancy arrives at the precinct where Holmes and Joan recount their puzzlement with Cassie passing two DNA tests until they realized that the shaved hair really was from Mina. Bringing Nancy into the viewing room of "the box", she sees a young woman being questioned. Having found a report of an assault where the victim's hair was shaved, they discovered the victim gave a fake name when hospitalized but was checked out by a Norman Ott. The assault occurred two days before Cassie was "discovered" by the FBI in the gas station bathroom. Ott lived near Mina's school in 2004 but moved away once he took her. Mina was discovered at Ott's new house and Nancy is told that her real daughter is the woman being questioned. Watson brings Nancy in the box to meet her where they hug and cry.
She remembers you and Richard.
Joan visits Henry at his house and apologizes for getting so angry about the book. She's fine with it being sold and shows Henry that she's edited the draft of the sequel. Henry invites her in to go over her edits. (♫ Oh Wonder - All We Do ♫) Holmes visits Cassie at a holding cell in the precinct where she shows her real personality, deceitful and amoral. She taunts him with varying versions of her age and won't concede that she attacked Mina, especially after Holmes tells her that neither Mina nor Norman Ott recognized her. She's extremely confident that she'll be found innocent of the murder of Robert Underwood as there's no murder weapon and, she's come up with six ways to explain how his blood came to be in the Davenport's SUV. She hopes Holmes will come to her trial and saying she thinks she can lie her way to freedom, she asks Holmes if he can tell if she's lying or not.