1942, in German-occupied Paris. Tahar Rahim ('A Prophet') stars as Younes - a young Algerian rogue, living on the wrong side of the law selling goods to fellow North African immigrants on the black market. In a time of oppression and radicalism, Younes is loyal only to himself and his family back home to whom he sends money regularly. His aim is simple - he plans to survive long enough to accumulate enough money to return home a rich man.
But his life changes when the police raid his apartment block, taking all of his contraband and arresting him. A deal is placed on the table: Become a spy at the local Mosque, or face an indefinite time in prison. 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.
As Younes goes deeper undercover into the Mosque, keeping a close eye on rector Si Kaddour Ben Ghabrit (Michael Lonsdale), he becomes drawn into a dangerous and morally complex situation - and must face a dilemma between serving his own best interests, or putting himself in mortal danger to save the lives of innocent people.