Remote. Mysterious. Deadly.

Situated off the Normandy coast, Mont Saint-Michel has been many things in its history: a prison, a siege fortress and an abbey. When Maggie and Laurent—who are struggling with the revelation of a family secret that threatens their marriage—take part in a couples' counseling weekend on the island, they are thrust head first into the setting for a brutal double murder. Because a once-in-a-century storm is bearing down on the island preventing communication with the outside world, their small group of six is trapped on the island—with a murderer. And the clock is ticking. Maggie has only one night to find the killer and elicit a confession before the police arrive and go with the obvious evidence—all of which points directly at Laurent.