
In this episode Lucy Liu sports horrendous hair, which is a rare occurrence.
Recap!
Sherlock and Joan are working a crime scene in a morgue. A bite mark on the victim has brought another investigator to the scene, thinking it might have something to do with the Aaron Coleville case. Two other victims with Coleville’s M.O., bludgeoned to death with identical bitemarks on the shoulder, have recently turned up, even though Coleville has been dead for nearly 10 years. The police are thinking they may have put away the wrong guy.
Sherlock quickly determines that the two cases are unrelated, but Joan talks to the other investigator, having been reminded of when Coleville died on the operating table under her superior’s scalpel in 2005. She goes to visit the man, Dr. Jonathan Fleming, wondering what exactly Coleville whispered to him before he died. Fleming is unwilling to talk and has no qualms about what happened that night. Joan is still suspicious, both about whether Coleville really was a murderer and whether Dr. Fleming let Coleville die because he believed Coleville guilty.
Joan lets Sherlock in on the case, and they use their friends at the anonymous internet hacking group called “Everyone” (by letting strangers punch Sherlock in the arm) to get their hands on dental records, sifting through them to find a perfect match to an ex-con who lives just a mile from one of the two murders. When they bring the man in, he exclaims that ‘a lot of people leave those bitemarks’. As it turns out, Aaron Coleville was a denture model during a previous stint in Newgate prison, and the prison now hands out dentures modeled on his teeth to any of its inmates who need them.
That leaves them with four suspects for the current murders, but all of them check out with alibis or other facts that take them out of the running. With no direction on the case, Joan investigates Dr. Fleming’s medical records, wondering if he’s made a habit of playing the role of judge with other people on his operating table. She explains to Sherlock her guilt over even considering letting Coleville die as well, and Sherlock encourages her to forgive herself for a less-than-noble, but understandable, thought that she never actually acted upon.
They go back to Newgate in the morning, and find that one of the dental assistants, Stan, is a former inmate, had dentures made for him off the record, and was convicted of sexual assault years ago. Of course, by the time the detectives figure all that out, Stan is on the lam. A search of his apartment shows he has stopped taking the chemical sterilization drug that suppresses his sexual desire, which makes him look even better for being the real culprit behind the Coleville murders. Joan also notices that Stan has a dog, who he may have taken with him on the run.
Sherlock gets to work on recovering Stan’s deleted social media accounts, dancing in a prom dress and singing songs from Frozen, while Joan agonizes and watches an interview with Aaron Coleville’s mother, who has been encouraged to sue the city for locking up her innocent son. Sherlock finds out that Stan’s dog is being treated for pancreatic cancer, and has an appointment with the vet for another treatment that very morning. They visit the doggie doctor, and spot Stan’s dog being brought in by one of Stan’s friends, who is helping him, unaware that Stan is wanted for murder.
Back at the station, Stan admits to having stopped taking the sex drive suppressant because of the havoc it was wreaking on his body, and that he has no al ibi for the nights of the two murders. Instead of being convinced of his guilt, however, Joan declares Stan’s innocence. Due to his finger being fractured just by him sitting on it, and also a picture of his leg in a cast after he ‘stepped awkwardly on the curb’, Joan suspects Stan has osteoporosis, a long-term effect of the sex drive suppressant. He’s now way too delicate of a man to have caused the damage at the scenes of the two recent murders.
So once again they are without a suspect, and once again a man might be going to jail for crimes he didn’t commit, due to Captain Gregson still wanting to proceed with prosecuting Stan. Dr. Fleming confronts Joan about her snooping into his past surgeries. To get her off his back, and to give her some peace about Coleville, Dr. Fleming tells her what Coleville whispered to him the night that he died. He claims that Coleville confessed his guilt over the two murders in 2005.
Joan is wary of immediately trusting Dr. Fleming’s words, but Sherlock points out this gives them a better perspective of the two more recent murders. Whoever is committing them now wants to cast doubt on Coleville’s guilt, but who would have anything to gain from that? Who else but Coleville’s poor mother, who has levied a billion-dollar law suit against the city for wrongfully convicting her son.