Garlat, a former cop, agrees with Voltaire's maxim, but when confronted with evidence manipulation in one of his former investigations, he is forced to ask himself other questions. Is memory selective? Did he really fabricate evidence? So who is he? And is this man in prison guilty? With his son, Nicolas, a cop like him, Garlat returns to Paris and takes up the investigation again.

Un ancien policier se demande s'il n'aurait pas manipulé des preuves dans une de ses anciennes enquêtes. En compagnie de son fils, il reprend le dossier à zéro.