1942, in German-occupied Paris. Younes, a young unemployed Algerian, earns his living as a black marketeer. Arrested by the French police but given a chance to avoid jail, Younes agrees to spy on the Paris Mosque. The police suspects the Mosque authorities, among which it's rector Ben Ghabrit (played by Michael Lonsdale), of aiding Muslim Resistance agents, as well as helping North African Jews, by giving them false certificates. At the Mosque, Younes meets the Algerian singer Salim Halali, and is moved by Salim's beautiful voice and strong personality. A deep friendship develops, and soon after Younes discovers that Salim is Jewish. In spite of the risks it entails, Younes stops collaborating with the police, and gradually develops from being a politically ignorant immigrant worker into a fully-fledged freedom fighter.