Chloé Muller, a young federal police investigator, is sent to ensure the transfer and protection of public enemy number one, Guy Béranger, a child murderer released on parole after 20 years in prison. He asks to be integrated into the Vielsart Abbey in a small remote village in the middle of the Ardennes. At the abbey, Béranger is entrusted to Brother Lucas, a young idealist monk to whom Abbot Mertens has given the mission of finding out the real intentions of the ex con who has requested to enter their order. At the village, the presence of the infamous murderer upsets the population and risks compromising the project of Patrick Stassart, the region's most influential businessman. He dreams of kick-starting the local economy by breathing new life into the family brewery in order to finance his disabled son's medical expenses. Everything radically changes for all of them when Noémie, a small village girl, mysteriously disappears. Chloé helps local police chief Michael Charlier find the girl as soon as possible while this case brings back painful memories for Chloé.