"A crazed killer escapes from an asylum and assumes the identity of his twin brother, a famous and respected architect."
Donna Mills
as Patty Heron
Ian Hendry
as Terry Spelling / Bob Spelling
David Lodge
as Bradley
Roddy McMillan
as Inspector Fillory
Robin Parkinson
as Mr. Holland
Susan Dury
as Jenny
Christine Shaw
as Woman
Seretta Wilson
as Sara
James Greene
as Policeman
Jonathan Dennis
as Intern
Susannah MacMillan
as Dorothy
Ralph Ball
as Dr. Styles
Hazel McBride
as Nurse
John Saunders
as Man
John Scholz-Conway
Director
Brian Clemens
Writer
Laurie Johnson
Music
John Cooper
Producer
Carole Legg
Editor
Al Pigden
Tom Rowland
John Willment
Stanley Mills
Production Design
Brian Grant
Camera Operator
Tony Mander
Mike Whitcutt
Paul B. Clay
Music Coordinator