The hilarity begins when professor Sherman Klump finds romance with fellow DNA specialist, Denise Gaines, and discovers a brilliant formula that reverses aging. But Sherman's thin and obnoxious alter ego, Buddy Love, wants out...and a big piece of the action. And when Buddy gets loose, things get seriously nutty. Scientist Sherman Klump's inventions, his upcoming marriage to his pretty colleague Denise Gaines, and his reputation, are threatened by his evil clone Buddy Love.