Based on the real-life spy, Mata Hari seduces a young soldier during World War II in order to get access to top secret documents.

Paris, 1917. German spy Mata Hari (née Margaretha Geertruida Zelle in Holland), posing as a Javanese dancer, is ordered by Ludovic to seduce French Capt. François Lassalle, thereby enabling another spy to steal secret documents. Although successful, she falls in love with the officer. Later, during a similar mission, Mata Hari is observed by François making love to Colonel Pelletier. Abandoned by François, Mata Hari flees to Spain, but she later returns to France to follow François to the front. They are reunited, but the next morning François is killed by a German patrol. In Paris Mata Hari is betrayed to the French by her German commanders. Arrested and convicted of espionage, she is shot outside the Château de Vincennes.