Scotland Yard is after a homicidal maniac called The Blue Hand, which is what he uses to kill his victims.
as Inspektor Craig
as Dave Emerson / Richard Emerson
as Dr. Albert Mangrove
as Lady Emerson
as Rechtsanwalt Douglas
as Myrna Emerson
as Schwester Harris
as Butler Anthony
as Edward Appleton / Die Blaue Hand
as Miss Mabel Finley
as Wärter Reynolds
as Robert Emerson
as Charles Emerson
as Richter
as Sir John