Caplan, Morlighem, Vachewski and Roxane arrest Lemoine, a big time bandit, after extracting information from his attorney. But the man is released on a technicality. Meanwhile, their charismatic team leader, Rossi, is accused of rape. A complaint has been lodged by Benaissa, a man questioned by Rossi about a murder case. The police inspection services get involved. In an effort to clear their chiefs name, the 4 cops set out to solve the murder case in which Benaissa is implicated. Their lives will never be the same again...