Summer 1910, North of France. Numerous tourists disappeared while relaxing on the beautiful Normandy beaches. Inspectors Machin and Malfoy soon understand that the epicenter of these mysterious disappearances must be Slack Bay, a unique site where the river Slack and the sea come together only throughout the high tide. There, lives a small community of fishermen and other oyster pickers. And in their bizarre stories will soon be involved the two curious characters. Especially in the complicated love story between the young Ma Loute, belonging to a humble family of the place, the Brufort, and Billie Van Peteghem, rampolla of rich bourgeois of the city, carefree tourists of the Bay. A love story destined to upset both families and all the protagonists of this grotesque and tragic story.