The wife of Casino owner Maxine Beauregard is poisoned to death in front of his friends and assistant. Camille and Lea are called to the scene, and all suspicions point toward the blacklisted gambler Roxie Roland. The problem is, there is no proof. After their mutual deal, Camille teams up with Harry, trying to solve the murder. As a conman, there is no one better suited than to take down another con woman. But as the evidence and the suspects pile up, it takes a high-stakes poker game to unravel the truth. With Camille's father in prison, Harry keeps his end of the bargain and gives Camille the name of the man threatening her father. He is already in Cannes.

Boire tries to run Camille off the road, but she manages to visit her father Philippe in prison. Camille and Lea are ordered to babysit arms-dealer and billionaire Leo Duval at The Majestic. Duval has been facing death threats, and it is rumored that the legendary assassin Nightshade is hired to kill him. Problem is that the Nightshade hasn't been seen for fifteen years. Harry acts as the guide and encyclopedia trying to stop the assassin, something that brings Camille and Harry closer. When the dead body of a former MI6 operative shows up, Camille realizes the Nightshade is still alive. The riddle gets even more complex as the night closes in. There are stronger motives than money.