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
