In World War II, an Italian miniature submarine's two-man crew secretly places mines on a British warship's hull while it's docked, leading to their capture and imprisonment as the British crew tries to uncover the true purpose of the sabotage.
The Valiant
During World War II, two Italian frogmen, on a covert mission to plant magnetic mines on a British warship, are captured by British intelligence and put through intense interrogation about their clandestine operation.
