A serial killer terrorizes London. Each victim is found with a telegram signed "The Marquis." There seems to be no other common thread between the victims, and Scotland Yard is baffled. Novelist and amateur sleuth, Paul Temple, is warned to stay away from the case, but he and his glamorous wife Steve can never refuse a good mystery.
John Bentley
as Paul Temple
Patricia Dainton
as Steve Temple
Peter Gawthorne
as Sir Graham Forbes
Valentine Dyall
as Bradley
Ronald Leigh-Hunt
as Inspector Ross
Grey Blake
as Storey
Dan Jackson
as Sakki the Valet
Ben Williams
as Roddy Carson
Robert Urquhart
as Slater
Christopher Lee
as Sir Felix Raybourne
George Patterson
as Servant Abdullah
Michael Mulcaster
as Sir Graham's Police Aide
