Synopsis

Kitty Winter, once the protégé of Sherlock Holmes, returns to New York after a three-year absence, bearing a grim warning. A killer is systematically eliminating those connected to a case they investigated together in London, and now they themselves are in the killer's sights. Sherlock, Kitty, Joan, and the NYPD must join forces to unmask the perpetrator. As the investigation unfolds, Watson discovers Kitty harbors a secret that will irrevocably alter the course of their lives.