Bank accountant Thomas Lieven is forced to work as a triple agent for the British, the French and the Nazis.

A respectable professor inherits a house and money in Montevideo from his wild sister, on the condition that he himself behaves in a disreputable way.

Firehand and his Apache friend Winnetou are determined to get justice for the murder of four young braves. They set off to track down the gang responsible for the horrendous act.