When their parents depart on a French vacation, sassy teenager Kathy (Scarlett Johansson) and her snotty little brother, George (Nick Fuoco), are left in the care of fun-loving Matilda (Eva Mendes). But the prank's on George after the nanny's magic rocks turn him into a pudgy porker. Matilda and the gang head to Mexico to find Grandma Berta (Renee Victor), who's their only hope for restoring George before Mom and Dad get home.