The first feature of the screenwriter Jacques Audiard is a clever thriller that fascinates as much for its ingenious, elliptical structure as for its noir-derived insights into obsession, loyalty and betrayal. Yanne's the salesman whose mid-life crisis coincides with his inadvertent involvement in the murder of a cop; as he sets out to trace the killer, his life begins to fall apart. At the same time, we witness the faltering growth of the friendship between seedy, aggressive con-man Trintignant and slow-witted innocent Kassovitz. Inexorably, but in surprising ways, the two stories gradually converge. And because it ends up admitting to the homo-erotic dynamics of the Trintignant-Kassovitz relationship, it's also, finally, rather more moving than the enigmatic early scenes lead one to expect.