When detective Mathias Rivoallan is found murdered by the gang led by the Nigerian Markudi, detectives Jimenez, Aurore, Ouessem and Tony decide to revenge the death of his friend. The vigilantes plot bloodshed, executing Markudi, his brother Bola (Doudou Masta) and the other gangsters in the abandoned building where they are gathered. However, things go wrong when the watchman arrives and the violent gang subdues the quartet and tortures them. Meanwhile, the lookouts of the gang hear explosions, sirens and the weird sound of the rabble.