Celebrity author Marcel moves with his wife (and publisher) Jeanne into their gigantic family mansion. When one day the young Gloria brings back their runaway dog, she promptly finds herself in their employ to nanny their daughter Lucie. What started out as a fragile idyll gradually fades as the stranger burrows ever deeper into the family—until it is clear that she pursues her own sinister goals. Belgian director Fabrice du Welz expertly pushes all the right buttons of the classic usurper thriller, with psychosexual undertones galore—and lets his elegant and unfathomable white-knuckle spine-chiller derail spectacularly in the third act.