"Sinbad" (John Phillip Law) is in possession of a rather clunky medallion that he only narrowly manages to keep from the grasping hands of the sorcerer "Koura" (Tom Baker). Finding safety in the city of "Marabia" he is told a tale by the Grand Vizier (Douglas Wilmer) and shown why the evil "Koura" is after his jewel. Shortly afterwards, while walking through the bazaar he is encouraged - to the tune of 400 gold pieces and the pretty "Margiana" (Caroline Munro) - to take the lazy "Haroun" (Kurt Christian) on his next, perilous, voyage. Off they all go in search of the Oracle of All Knowledge - ...