When Joan revisits one of Sherlock’s cold cases, she discovers an unsolved murder is connected to a rare prehistoric fossil. Meanwhile, Sherlock finds himself in uncharted territory when his duties as a sobriety sponsor cross his personal boundaries.
When a body is found in a barrel, Holmes and Watson launch an investigation into the mafia’s ties to the murder. Meanwhile, Sherlock attempts to make amends with Detective Bell.
Holmes and Watson come face to face with Moriarty when their one-time adversary is brought in as a consultant on a kidnapping case. Meanwhile, Detective Bell continues his struggle on the road to recovery.
When a hedge fund manager who was also running a Ponzi scheme is murdered, Holmes and Watson must determine which of his clients is guilty. Also, Sherlock contemplates sponsoring a fellow recovering addict.
When an investigation goes horribly wrong, Sherlock must testify in an official police inquiry which jeopardizes his and Watson’s future with the NYPD.
Holmes and Watson uncover the identity of a serial killer whose case has gone cold and find themselves butting heads with the NYPD.
When a beautiful young woman is murdered, Holmes and Watson investigate her ties to a billionaire CEO. Mycroft makes a case for Sherlock to move back to London.
Sherlock’s brother, Mycroft, arrives in New York and enlists Holmes and Watson to help solve a case involving his former fiancée. Meanwhile, Sherlock has a difficult time accepting Mycroft and Joan’s relationship.
When Captain Gregson’s home is invaded, Holmes and Watson work to find the masked gunman before he strikes again. Meanwhile, Gregson gives his team some insight into his private life.
Holmes and Watson find themselves digging through the dark world of the mob to find a killer when they discover the body of a former assassin. Meanwhile, Watson helps a close friend track down a mystery man who swept her off her feet.