Would-be comedian Rupert Pupkin (Robert De Niro) is a failure in life, but a celebrity in his own mind. When he meets talk show host Jerry Langford (Jerry Lewis), he’s convinced it will provide his big break, but Langford isn’t interested. Undaunted, Pupkin begins to stalks Langford – and when that doesn’t work, he kidnaps him, offering his release in exchange for a guest spot on Langford’s show.