After leaving the British Secret Service, David Somers (played by Trevor Howard) finds work cataloging butterflies at the country house of Nicholas and Jess Fenton. After the murder of a local gamekeeper, suspicion (wrongfully) falls on their niece, Sophie Malraux (Jean Simmons). Somers helps Sophie to escape arrest and they go on the run together. After a cross-country chase they arrive at a coastal city with the intention of leaving the country by ship. All's well that ends well after the true identity of the murderer is revealed.
Jean Simmons
as Sophie Malraux
Trevor Howard
as Maj. David Somers
Sonia Dresdel
as Jess Fenton
Barry Jones
as Nicholas Fenton
Kenneth More
as Willy Shepley
Geoffrey Keen
as Police Inspector
André Morell
as Secret Service Chief Chubb (as Andre Morell)
Michael Brennan
as Police Superintendent
Gerard Heinz
as Dr. Karl Cesare
Lily Kann
as Minna Cesare
Eric Pohlmann
as Taxidermist
Richard Wattis
as Employment Agent
