Luisa has all she needs to be happy: she lives with Mathieu, the man she loves, and Arthur, Mathieu's 6-year-old son by his first wife, who died in an accident. But Arthur, whom Luisa has been raising like her own, suddenly disappears from school and no one claims a kidnapping. The lies on which the young woman built her relationship with Mathieu are coming back to haunt her. Suspected by both Mathieu and the police, Luisa has to fight to prove her innocence while a trap closes around her.