Patrick Wymark as Inspector Holloway

Margaret Johnston as Mrs. Von Sturm

John Standing as Mark Von Sturm

Alexander Knox as Frank Saville

Judy Huxtable as Louise Saville

Don Borisenko as Donald Loftis

Thorley Walters as Martin Roth

Robert Crewdson as Victor Ledoux

Colin Gordon as Dr. Glyn

Tim Barrett as Morgan

Frank Forsyth as Tucker

Olive Gregg as Mary

Harold Lang as Briggs

Gina Gianelli as Gina

Peter Diamond as Junk Yard Man

John Harvey as Reinhardt Klermer