A lonely woman puts her house at the disposal of teenagers who want to hold parties without being disturbed. Young people can say “Ma”, they can have fun as they want in the basement of her house, but they can not swear, one of them must be awake, and they can not go upstairs. It’s an arrangement that looks ideal for adolescents eager to have fun unattended. But they will quickly find that nothing in life is free, and that their dream come true will prove to be the most terrible nightmare in their lives.