Carrie O'Toole Selton, an eccentric and superstitious Boston landlady, was found strangled by her own red scarf. In her had was a note: ""The Stroke of Death. May it forever part our ways."" Her ancient house on Brattle Street was sinister enough at best; a corpse did not help the abience. Nor were the assorted tenants Mrs. Selton had collected (because she had ""seen them in the cards"") calculated to inspire confidence. Inspector Green of Boston Homicide was given the thankless task of plucking a murderer out a group of suspects, any of whom could have been legitimately judged insane!