The Moochmore girls are certain they all suffer from some kind of undiagnosed mental illness - because if they're not crazy then they're just unpopular. Their mother Shirley - unable to cope with her demanding daughters and unsupported by her philandering politician husband, Barry - suffers a nervous breakdown. After Barry commits his wife to a mental hospital (telling his constituents that "she's on holiday") he finds himself alone with 5 teenage girls he barely knows. Desperate, he impulsively picks up a hitchhiker named Shaz and installs her in his home as nanny to his daughters.
