Clément Royan is called in on a murder case. But the case takes a completely different turn when the victim turns out to be a former employee of the casino run by his grandmother, Denise Royan. Clément must reconnect with his family, who made their fortune in casinos, but with whom he became estranged when he chose a career in law enforcement over the family business. Juggling ancient Norman customs and family secrets, Captain Royan must also collaborate with a former colleague for whom he still has feelings. Clément will have no choice but to keep his cool in order to solve this mystery that looms over the Normandy coast.