1672. Off the coast of Greece, a band of former slaves led by Captain Peter Wolf and his first mate Monastir, mutiny against their slaver Captain Annetti, and seize a Venetian ship called the Salty Dog carrying a cargo of salt. They force Annetti and the Venetian captain Ivanich to walk the plank, and are rid of them. They decide to sell the salt in Cyprus and take their freedom as privateers under the flag of Tunis.
Onboard is the Bavarian ship owner's daughter, Sissy Ortenburg, haughty and spoiled, who rebuffs Wolf as a pirate. They sail for Cyprus where Sissy becomes an object of desire for the Governor of Famagusta who kidnaps her, imprisons the crew of the Salty Dog and steals its cargo.
Breaking out of prison, Wolf and his men free Sissy but kill the Governor in the process. As they flee for Tunis, Annetti and Ivanich (who is in love witth Sissy), rescued by fisherman, arrive in Famagusta and cheat a captain of his ship and crew, then give chase to the Salty Dog.