Niémans is called in the middle of the night by Marek Volsnic, a former robber who seems to know him well. As he rushes to the spot, Marek is found unconscious by a guard in his cell, alongside another comrade, mutilated face, lacerated body, eyes gouged out. Niémans, with the agreement of the prison director, investigates under the radar with the help of Camille. The latter, feeling that Niémans is hiding the real reason for their presence here, renews ties with Kleinert. Very quickly, they discover that Niémans is covering up a terrible secret from his past. An investigation that will tip Niémans to the other side of prison and where Camille will have to redouble her efforts to save her mentor...
