Salvage submarine captain Robinson got sacked by his company. His fellow Kurston talks of a wreck of a lifetime, a downed Nazi sub in the Black Sea which was carrying blackmailed Soviet gold. They get a private backer and Robinson asks for a crew of twelve men, half Brits and half Russians. Robinson and Kurston make their list, reluctantly accepting their colorful attitudes. They get their ride, a rust heap of a sub, in Sevastopol and then get going, diving soon enough so to avoid detection from the Russian Black Sea fleet. The backer insist that his banker Daniels tag along the ride. Soon the crews attitudes become a clear ticking time bomb as the British psychopathic diver Fraser picks a fight with the Russians and accidentally kills Kurston, the only one apparent interpreter between them.