A tightly controlled mountain town. A disappearance no one wants solved. And something in the surrounding peaks that refuses to stay buried.

In the dead of winter, detectives Frank Sangaré and Ms. Umber arrive in Saint-Elme, a remote village in the Alps famed for its mineral water—where residents have learned to mind their own business.

The pair is investigating the disappearance of a wealthy young man who vanished three months earlier. But in Saint-Elme, power flows through the Sax clan, and the local police serve at their pleasure. Thinly veiled threats maintain the peace, and everyone knows where the lines are.

As Sangaré and Umber push forward, they see the high cost of challenging that order—but then the boundaries start to shift. Frogs have flooded the streets. People are seeing things they shouldn’t. And the case pulls the detectives into something beyond the reach of money or influence.