Daredevil sailor Sinbad (Douglas Fairbanks Jr.) embarks on a voyage across the Seven Seas to find the lost riches of Alexander the Great. His first stop is the port of Basra, where his ship is seized and scheduled for auction. In his attempt to win it back, he befriends beautiful concubine Shireen (Maureen O'Hara). But when her master, the nefarious Emir (Anthony Quinn), calls her back to duty, Sinbad must interrupt his adventure to save the "Jewel of Persia."