When a pair of thirtysomethings let one of their mothers over the threshold, they have no idea that he has just been placed in intimate purgatory. A peaceful life is slowly turning into a chaotic wreck. Valerie, a fistful of sixty-somethings, is an energetic diva who, step by step, conquers not only the space of the apartment but also the minds of its inhabitants. The creeping home invasion is gaining momentum, certainties are shaken, the boundaries of privacy are eroding. Are mothers and mothers-in-law always right? Do they mean well with us? And isn't that sometimes why they are the biggest monsters?