British crime film directed by Peter Duffell and starring Bernard Lee, Moira Redmond and John Van Eyssen, loosely based on the 1918 novel "The Man Who Knew" by Edgar Wallace.

Bernard Lee
Inspector Mann

Moira Redmond
Freda Strickland
Stanley Morgan
Sergeant Rutledge

John Van Eyssen
Merril
Gordon Boyd
Rex Holland
Mark Singleton
Shilton
Victor Platt
Harold Strickland

Ernest Clark
Ashton

Nicholas Smith
Pawn Shop Assistant
Larry Martyn
Pete Lake
Danny Sewell
Avery
Robert Sansom
Doctor
Richard Shaw
Bill Cross
Graham Leaman
Ballistics Scientist
Hilary Martyn
Rita