Freed after 20 years in prison, the child killer Guy Beranger found refuge with the monks in Vielsart, a small village in Belgian's Ardennes. He is placed under the protection of a young Federal Police's inspector, Chloé Muller. A little while after his release, a little girl disappears.

A troop of scouts arrives at Warnaffe for their big summer camp. Among them, the newest member of the Coyotes patrol, Kevin, a rebellious and lonely boy. From the first evening, he leaves to find something to smoke in the neighbouring village. There he meets Marie with whom it's love at first sight. They spend the night by a lake in a quarry. The next day, still under the influence of drugs, Kevin dives into the lake, discovers a cave, diamonds and a corpse of a young man. This is where problems started.

Hunting down killers to help bereaved families get justice is more than just a job; it’s a duty for Thomas Bareski, a retired, hotshot police detective eager to reopen unsolved murder cases in a mission to find the culprits.