"A London solicitor and a French detective investigate the mysterious death of an elderly woman suspected of being poisoned."
Oskar Homolka
as Inspector Hanaud
Robert Urquhart
as Jim Frobisher
Yvonne Furneaux
as Betty Harlowe
Josephine Griffin
as Ann Upcott
Harold Kasket
as Boris Wabersky
Ruth Lodge
as Nurse
Pierre Lefevre
as Detective Maurice Thevenet
Pierre Chaminade
as Detective Moreau
Jacques Cey
as Police Commissaire Giradot
Anthony Nicholls
as Lawyer Jarrett
Michael Anderson
Director
Edward Dryhurst
Writer
A.E.W. Mason
Novel
Gerald Crossman
Music
Eric Aylott
Makeup Artist
Robert Lennard
Casting
Thelma Orr
Script Supervisor
Erwin Hillier
Director of Photography
Polly Young
Hairstylist
Edward B. Jarvis
Editor
Vaughan N. Dean
Producer
Terence Verity
Production Design
Les Hammond
Sound Recordist