A young couple - Paul, a music producer, and Miriam, an aspiring lawyer - hire a nanny for their children - a middle-aged widow who has a separate adult daughter. Paul and Miriam are pleasantly surprised by how well Louise approached them: she won the hearts of children by inventing more and more exciting games, and became a cook and housekeeper. The apartment has never been so clean, and there is so much delicious food on the table. But over time, the couple discover that they have become dependent on their perfect nanny...