Julien is a former paratrooper, who now works for millionaire arms dealer Simon Carala. He is in love with Florence, Carala's wife. They plan to murder him and make it look like a suicide, but Julien forgets a rather important detail. Leaving the engine of his sports car running, he races up to the office to retrieve it, but fate intervenes, and Julien misses his rendezvous with Florence. She spends the night wandering the Parisian streets alone....