Milo Malart, detective of the Catalan State Police, faces a particularly cruel and complex case.
Monday at dawn a young man shows up at the police station covered in blood from head to toe. "Everyone is dead," he whispers before fainting. Analysis of his clothes confirms that the blood belongs to at least three people. Are the police looking at yet another victim, the survivor of a massacre? But why does he remain silent when he regains consciousness? There is another possibility: that he is the murderer. However, everyone describes him as a docile boy, unable to hurt a fly. Who is Lucas Torres really?