It's been several years since Jack the Ripper held London's East End in his grip, but has he returned? Three young women from respectable Mayfair have been found, strangled. The police call in a consultant, Dr. Karl Schermann, a popular "psycho-graphologist" who claims to discover a person's character by analysis of handwriting. Holmes is convinced the man is a charlatan, but turns his attention to other cases: theft from an auction house, and a blackmail in Sussex that hints at something much more dangerous. In London, yet another young woman has been killed; before he can look into that matter, Holmes must show London the truth about Dr. Schermann.