Narrowly evading a terrible sea monster (with Shazzan's help), Nancy and Chuck find themselves on an island, and there they discover a bottle. They open it, and from it emerges the Evil Demon of the Bottle, who has been trapped for 4,000 years. The Demon wants revenge on the one who trapped him, and has learned a great deal of evil magic during his imprisonment. And who trapped him? Why, Shazzan, of course!