"In a vein similar to Bond movies, a British agent Philip Calvert is on a mission to determine the whereabouts of a ship that disappeared near the coast of Scotland."
Anthony Hopkins
as Philip Calvert
Robert Morley
as Uncle Arthur
Nathalie Delon
as Charlotte
Jack Hawkins
as Sir Anthony Skouras
Corin Redgrave
as Hunslett
Derek Bond
as Lord Charnley
Ferdy Mayne
as Lavorski
Maurice Roëves
as Lt. Williams - Helicopter Pilot
Leon Collins
as Tim Hutchinson
Wendy Allnutt
as Sue Kirkside
Peter Arne
as Capt. Imrie
Oliver MacGreevy
as Quinn
Jon Croft
as Durran
Tom Chatto
as Lord Kirkside
Charlie Stewart
as Sgt. Macdonald
Edward Burnham
as Macullum
Del Henney
as Dungeon Guard
Bill Brandon
as Thug (uncredited)
Harry Fielder
as Thug on Boat (uncredited)
Martin Grace
Charles Gray
as Sir Anthony Skouras (voice) (uncredited)
Prentis Hancock
as Agent (uncredited)
Barrie Hesketh
as Seaman (uncredited)
Bill Hibbert
George Leech
Étienne Périer
Director
Alistair MacLean
Novel
Screenplay
Walter Stott
Compositor
Arthur Ibbetson
Director of Photography
Denis Holt
Associate Producer
John Shirley
Editor
Sue Yelland
Costume Design
Ted Lloyd
Production Supervisor
Elliott Kastner
Producer
Angela Morley
Original Music Composer
Jack Maxsted
Art Direction
Malcolm J. Christopher
Location Manager
David Wynn-Jones
Assistant Camera
Les Hillman
Special Effects