A car drives into the forest with two scared girls trapped in the boot. The next day, Florence Grangeon reports the disappearance of Laura and Juliette Sorin, her 5- and 8-year-old daughters, to the DIPJ in Lille. She and their father, Franck Sorin, had joint custody of them, and he is missing too. Arnaud, the grandfather, wealthy owner of a luxury hotel chain, considers Franck a marginal follower of collapsology theories, trying to live on a eco-responsible farm. He is the ideal suspect in their probable kidnapping, for his father-in-law would do anything to dispute the custody of his daughters.