When 7-year-old Farmer twins Kelly (Mary-Kate Olsen) and Lynn (Ashley Olsen) discover that Aunt Agatha's (Cloris Leachman) supernatural powers are enabled by a mystical moon stone, they set out to wrest the stone away from her. After all, the girls learn that their family's deep financial troubles point to Aunt Agatha, whom they're stunned to learn is a witch. Eric McCormack and Phil Fondacaro co-star.