Ariel, a young French Jew, decides to leave his family to go to Israel and secretly become an agent of Mossad, the Israeli secret service. After years of training, his first mission is in Paris to steal secrets from Remy Prieur, a French atomic scientist.
Five highly-trained KGB agents are sent to the west to assassinate several Soviet dissidents. In order to stop the diabolical plot, an American agent must infiltrate Soviet intelligence and obtain information from a Russian computer.
In the German-occupied Paris, Helene is torn between the love for her boyfriend Jean, working for the resistance and the German administrator Bergmann, who will do anything to gain her affection.
