Czechoslovakia, March 1939, on the eve of World War II. As the German invaders occupy Prague, inventor Axel Bomasch manages to flee and reach England; but those who need to put his knowledge at the service of the Nazi war machine, in order to carry out their evil plans of destruction, will stop at nothing to capture him.

• Gainsborough Pictures
• Margaret Lockwood
• Rex Harrison
• Paul Henreid
• Basil Radford
• Naunton Wayne
• James Harcourt
• Felix Aylmer
• Wyndham Goldie