The mysterious vigilante Milton has warned Scotland-Yard of his intention to kill the lawyer Maurice Meister who is the cause of his sister's suicide. Police and detectives watch over the lawyer's home, but on the day and at the appointed time Meister is murdered.
Lawyer Maurice Meister
Inspector Berry
Cora Milton
Mary Lengley
Doctor Lomond
Inspector Bliss
Sam Hackitt
Colonel Davis
Johnny Lengley
Thomas, detective