Julien is woken by a frantic message on his mobile phone from Lea asking him to call her. Molina and his team trace the call to the train station. Nicolas, a waiter at Morel and Sons restaurant, shows Julienthe illegal police radio interceptor he has in his car, and as Julien listens to the communications, he begins to shadow their investigations.

Francis Dupuis is interrogated, but he is obviously confused and unclear about details. However, when the police search his property they make a surprising and convincing discovery.

The waiting is finally over for the Morel family. Julien becomes obsessed with identifying everybody who attended the birthday party.