While Max narrowly escapes death, Lucie and Jean-Guy investigate the violent and disconcerting attack on a minibus. Meanwhile, Wendie, Léa, and Nathan dig deeper into the symbol drawn by Mammig. But while they find valuable clues, they are trapped inside the retirement home...

Refusing to believe the case is closed, Max loses his footing. Wendie, meanwhile, uncovers secrets surrounding her mother's death and confronts her father. This gives them the opportunity to revisit Sarah's final day and the causes of her death.