Paul Temple
Steve Temple
Sir Graham Forbes
Mrs. Weston
Mrs. Morgan
Jacqueline Giraud
Professor Hardwick
Oliver Ffollett
Van Draper
Major Murray
Bill Bryant
Dr. Steiner (as Leo De Pokorny/Leo de Pokorny)
Hammond
Inspector Crane
Rikki
Ernie
Mr. Weston
Celia Hardwick
Post Office Engineer
An Interested Visitor
Doctor
Nurse
1st Gangster (as Denis Val Norton)
2nd Gangster
Hotel Guest (uncredited)