Sherlock Holmes comes out of rehab and jumps straight into consulting with the NYPD, dragging his new sober companion, Joan Watson, with him. Their first case takes them to a home invasion gone wrong.
Sherlock's powers of deduction get tested when a young man is murdered entering his own apartment. Watson's personal life comes to light, when she has dinner with an ex.
Sherlock gets a chance to take down a long running serial killer nicknamed "The Balloon Man".
Despite his loathing of bankers, Holmes takes a private consulting case covering the death of a Wall Street executive who appears to have overdosed on Heroin. Despite the close proximity to narcotics he convinces Watson to re-enter the dating scene.
Sherlock discovers that someone has been secretly murdering the patients at a hospital. He also learns more about Joan's "disgrace" from the medical world.
Sherlock attempts to prove that there was a murder victim mixed in with a plane crash. Watson tries to convince Sherlock to meet with his father.
Sherlock steps in to help Captain Gregson figure out a double homicide that mimic's one of Gregson's old cases. After Sherlock gives her the cold shoulder, Watson leaves Sherlock alone for the day to visit Hemdale and try to develop some insight on him.
While investigating an office building explosion, Sherlock discovers a long running crime in progress. Watson encourages Sherlock to pick a sponsor.
Sherlock's eyes get opened up to some eastern culture when he takes on the case of a dead college professor. Watson is called on by an ex who needs her help.
Sherlock gets a private request to investigate an "impregnable" vault known as the Leviathan. He still manages to surprise Joan by arranging things to meet her family.
Sherlock and Watson investigate the murder of the manager of an up-scale Manhattan Hotel, whose body is found inside a washing machine. Despite her insistence on leaving, after finishing their contract, Sherlock offers Watson an apprenticeship.
Some unfinished business, a British serial killer known as "M.", has shown up in New York and challenges him again. Being faced with his history puts Sherlock in a place that makes Watson rethink her decision to take a new client.
Even though he's suspended from the NYPD, Sherlock get's himself involved in the investigation of a conspiracy theorist's suspicious death. Forced to work around their problems, Watson tries to patch things up between Captain Gregson and Sherlock.
Sherlock is forced to work with an old acquaintance, Profiler Kathryn Drummond, when they pursue a serial killer who has studied his own profile and wants revenge. Mixed in with the messes Watson deals with being evicted from her apartment.
When a friend's daughter gets kidnapped Sherlock agrees to help without involving the NYPD. Watson has to work a little harder when she finds out that the friend was also his drug dealer.
The attempt to murder Detective Bell should be a pretty text book case, but things go sideways when the obvious suspect gets killed.
Sherlock takes a private case when a philanthropist with dementia believes that someone is murdering him. He also starts to officially train Watson by sending her on errands and having her present her own theories on their case.
Joan's first case has her tracking a woman who disappeared after leaving her husband a break up video, in which she mentions a murder that Sherlock has decides to investigate.
A simple robbery-homicide case gets crazy when a winter storm cuts the power to the entire North East. Watson insists that Sherlock learn some roommate etiquette when he invites a friend who is having man trouble stay in the brownstone.
Amid resisting the celebration of his first year of sobriety, Sherlock takes on a very sensitive case involving the fail safe of a blackmailer.
When a man who had been on Sebastian Moran's hit list dies, Sherlock resumes the hunt for Moriarty.
Sherlock and Watson take a case handed directly to them by Moriarty, hoping hoping it will bring them closer to the man himself. Gregson shows his concern for Watson by encouraging her to take on a another Sober Companion client.
Sherlock's world gets flipped around when Irene is returned to him. Their past is revealed through a number of flashbacks.
Sherlock and Watson attempt to take Moriarty head on.