A group of adventurers refloat a WWII German submarine and prepare to use it to pull a very large heist; The Queen Mary which they plan to rob on the high seas.

Passengers on a ship traveling from Mexico to Europe in the 1930s represent society at large in that era. The crew is German, including the ship’s Dr. Schumann, who falls in love with one of the passengers, La Condesa. A young American woman, Jenny, is traveling with the man she loves, David. Jenny is fascinated and puzzled by just who some of the other passengers are.