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
Trevor Howard
Sonia Dresdel
Barry Jones
Kenneth More
Geoffrey Keen
André Morell
Michael Brennan
Gerard Heinz
Lily Kann
Eric Pohlmann
Richard Wattis
Sandra Dorne
Maire O'Neill
Maxwell Reed
Marianne Stone