March 1934. Revered mystery writer Josephine Tey is traveling from Scotland to London for the final week of her play Richard of Bordeaux, the surprise hit of the season, with pacifist themes that resonate in a world still haunted by war. But joy turns to horror when her arrival coincides with the murder of a young woman she had befriended on the train ride—and Tey is plunged into a mystery as puzzling as any in her own works.

Detective Inspector Archie Penrose is convinced that the killing is connected to the play, and that Tey herself is in danger of becoming a victim of her own success. In the aftermath of a second murder, the writer and the policeman must join together to stop a ruthless killer who will apparently stop at nothing.