Barry Jones

Professor John Malcolm Francis Willingdon

André Morell

Superintendent G.W. Folland

Olive Sloane

Goldie Phillips

Sheila Manahan

Ann Willingdon

Hugh Cross

Stephen Lane

Joan Hickson

Mrs. Emily Georgina Peckett

Ronald Adam

Arthur Lytton, the Prime Minister

Marie Ney

Mrs. Willingdon

Joss Ackland

Station Policeman

Marianne Stone

Woman in Phone Box

John Stratton

Army Mechanic

George Spence

Man on Bus (uncredited)