"When young reporter and amateur biker Jerry Marsh investigates a mysterious hooded figure on a motorbike, he discovers crooks hiding out in a ruined castle with atomic sabotage on their minds..."
Jimmy Hanley
as Jerry Marsh
Rona Anderson
as Mary Plack
Leslie Dwyer
as Robert Plack
Lionel Jeffries
as Martin Bremner
Kenneth Connor
as George Amble
Beatrice Varley
as Mrs. Marsh
Michael Golden
as Rakoff
Valerie Hanson
as Karen
Vincent Ball
as Ted Lintott
Edwin Richfield
as Geoff Morgan
Robert Rietti
as Mario
James Raglan
as Rackton
Frank Atkinson
as Landlord
Edie Martin
as Elderly Lady
Peter Swanwick
as Holiday-Maker
Sarah Davies
as Holiday-Maker's Wife
John Pike
as Holiday-Maker's Son
Anne Gilleno
as Joyce
John Baker
as Van Driver
Wolf Rilla
Director
Wilfred Burns
Original Music Composer
W. H. Lindop
Sound Recordist
John Stoll
Art Direction
Leo Rogers
Camera Operator
A.R. Rawlinson
Producer
Jane Buck
Script Supervisor
Jim Rance
Makeup Artist
John Trumper
Editor
Geoffrey Faithfull
Director of Photography
Writer