One evening, writer and former war reporter Bastien Grimaldi is beaten up by a group of men in the street without cause. Back from hospital, he tries to return to his everyday life as best he can. But he can't let go of the mysterious incident, especially as strange phone calls, blackmail attempts and even a car bomb attack follow. Bastien calls in the police. When they are unable to help him, he decides to take matters into his own hands and meets a certain Sylvain Hagner. He is a criminal on record who has already blackmailed six other victims before him. Hagner demands one billion francs from Bastien. A considerable sum that he is unable to raise - until his investigations lead him to an old family secret. His mother has concealed from him the possession of four paintings by Degas, Dufy, Renoir and Picasso. How did Hagner find out about these valuable possessions? A criminal network is revealed that leads all the way to divided Berlin, where a showdown ensues.