A husband-and-wife detective team look into the murder of one of her friends, whose father--a prominent scientist--has been kidnapped. They find themselves up against a sinister crime organization headed by a mysterious figure known only as "Z".

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Main Cast: John Bentley, Dinah Sheridan, Jack Livesey, Beatrice Varley, Barbara Couper, Jenny Mathot, Andrew Leigh, Hugh Dempster, Dino Galvani, Ivan Samson

Director: Maclean Rogers

Writers: Francis Durbridge, A.R. Rawlinson

Editor:

Cinematographer: Brendan J. Stafford

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