Sailing to Baghdad after a narrow escape from the monster island of Colossa, the wedding plans of legendary hero Sinbad (Kerwin Mathews) and Princess Parisa (Kathryn Grant) are spoiled by the scheming sorcerer Sokurah (Torin Thatcher). In return for his previous help with the cyclops on Colossa, Sokurah demands that Sinbad retrieve a lamp he lost on the island. When Sinbad refuses, the conjurer shrinks Parisa, forcing the sailor and his crew back to the high seas in order to save her.