An evil French woman, is a spy for the Germans during World War I. She vamps and seduces officers of the French high command, accumulating state secrets and then discarding her lovers. Chaumontel is the mistress of Captain Henry Ravignac (played by Storm). She steals some papers from him and gives them to the Germans, then escapes to Berlin. He is tried and found guilty of neglect. He then commits suicide. His brother, Lieutenant Charles Ravignac (played by Hickman), vows revenge on Chaumontel. Pretending to be a spy, he goes to work for the Germans and becomes her assistant. He poses as a chauffeur of her phony countess.