James Mason as Nicholas Cunningham

Ann Todd as Francesca Cunningham

Herbert Lom as Dr. Larsen

Hugh McDermott as Peter Gay

Albert Lieven as Maxwell Leyden

Yvonne Owen as Susan Brook

David Horne as Dr. Kendall

Manning Whiley as Dr. Irving

Grace Allardyce as Nurse

John Slater as James

Muir Mathieson as Conductor