A German living in India during World War II is blackmailed by the English to impersonate an SS officer on board a cargo ship leaving Japan for Germany carrying a large supply of rubber for tyres. His mission is to disable the scuttling charges so the captain cannot sink the ship if they are stopped by English warships.

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.