Set largely within prison walls, the film details the prison career of Malik el Djebena (Tahar Rahim), a 19-year-old man of North African origin but estranged from the Muslim community. Sentenced to six years for what appears to be violence against police (albeit denied by Malik), he is chosen by Cesar Luciani (Niels Arestrup), feared kingpin of the prisons reigning Corsican gang, to kill a prisoner named Reyeb (Hichem Yacoubi) who had initially offers Malik drugs in exchange for sex. Reyeb is in prison awaiting testifying against the mob. Malik commits the bloody murder, and thanks to Luciani's near-total control of the prisons internal workings - gets off scot-free. This makes him a lieutenant in the prisons Corsican gang, initially entrusted only with menial duties and disparaged as an Arab outsider.