Roberta and Suzana are two sisters, both in their thirties, of totally different beauty and life styles, united by a common goal: to take revenge on their grandmother, a mean old woman who, in the past, turned the little girls' lives into hell, with her strict educational concepts. Since they were very young, the two sisters plan to kidnap the grandmother and now is the long awaited moment. Before Roberta and Suzana leave to the beach house, the setting of their grandmother's terrorist practices, Roberta, while waiting for Suzana at a restaurant, meets Renato, an extremely proper guy who ends up involved in this unexpected adventure. The two sisters' departure leaves Suzana's husband, Alberto, bewildered and he ends up being also part of a parallel mad adventure.