Wenger-Printz, a decidedly very lucky player, accumulates winnings at the blackjack table of a large casino. Didier Cassard, the director of the establishment, suspects him of cheating. Alongside Wenger-Printz, an ambitious player, Fabienne, is trying to hit the jackpot. To complete this line-up of specialists, Anita Fargier arrives. The latter, inspector of the gaming police, has the mission to monitor Wenger-Printz and check if he is honest. Anita is surprised to find that, as soon as she arrives, Wenger-Printz loses blow after blow. All of his previous earnings go there. Anita leaves empty-handed. As she stands in the parking lot, she is coldly shot. Judge Alice Nevers inherits the case
