
An international criminal arrives in London, and a detective is anxious to pin something on him for some unprovable murders of former lovers. The villain starts to suspect servants and henchmen of being a police spy known as "Number Six".
Cast

Ivan Desny
Charles Valentine

Nadja Regin
Nadia Leiven

Michael Goodliffe
Det. Supt. Hallett

Brian Bedford
Jimmy Gale
Joyce Blair
Carol Clyde

Leonard Sachs
Weiland
Maxwell Shaw
Luigi Pirani

Harold Goodwin
Smith

John Welsh
Assistant Commissioner

Barrie Ingham
House Agent

Derrick Sherwin
Det. Sgt. Waters
Malou Pantera
Lotte
Andre Mikhelson
Head Waiter
Josephine Gordon
Mrs. Pirani
Norman Florence
Waiter
Crew

Robert Tronson
Director
Philip Mackie
Screenplay
Derek Holding
Editor
Bert Mason
Director of Photography
Gordon Gilbert
Assistant Director
Jack Greenwood
Producer
Herbert Smith
Camera Operator
Ronnie Curtis
Casting Director
Hilda Fox
Hairdresser
Michael Morris
Makeup Artist
Brian Blamey
Sound Editor
Ronald Abbott
Sound Recordist
Sidney Rider
Sound Recordist
Bernard Ebbinghouse
Original Music Composer
Harry Kratz
Production Manager

Edgar Wallace
Original Story
Peter Mullins
Art Direction