DVD: A Prophet (18)

Petty criminal Malik El Djebena (Tahar Rahim) enters prison as a blank canvas – he has little education, no family, no friends and no enemies – and apart from one clue ("what do you do besides attacking cops?") it's not clear why he's been given a six-year sentence.

The 19-year-old is soon greeted with a brutal mugging for his trainers before being targeted by the feared top dog, Cesar Luciana (Niels Arestrup), of the Corsican mafia who rules the prison. Cesar orders Malik – "If you don't kill him, I kill you" – to bump off an Arab inmate, Reyeb (Hichem Yacoubi), who is due to testify against him. Malik has no choice. Prison will make him a career criminal, and a depressingly successful one. His horrific assassination of Reyeb, with a razor blade, gains him "servant" status for the Corsicans and he gradually gains Cesar's confidence. He also learns to read and write, teaches himself Corsican and builds his own drug-selling power base.

Jacques Audiard's Cannes Grand Prix winner captures the look, the stench, the squalor and the violence of prison life – no loveable Norman Stanley Fletcher (Porridge) rogues here, just beatings in the showers and ethnic hatred in the courtyard. Rahim is compelling as Malik, but we could have done with a tad more background information about him. Nevertheless, this epic and provocative gangster drama never flags and the superb Arestrup makes for a suitably vicious Mob boss.