Synopsis: China Seas proved that the recently imposed Hollywood production code had little if any effect on the popularity of MGM sex symbols Clark Gable and Jean Harlow. Gable plays the captain of a tramp steamer chugging between Singapore and Hong Kong. Harlow is Gable's ex-main squeeze, a "woman of the world" who books passage on the steamer at the same time that another of Gable's former loves, aristocratic Rosalind Russell, shows up. Wallace Beery plays Gable's supposedly lovable first mate, who is actually in league with a gang of pirates who plan to steal the gold shipment being carried in the hold of the steamer. Harlow tumbles to Beery's secret, but is unable to convince Gable, who is sore at Harlow for mean-mouthing Russell. Out of pique, Harlow casts her lot with the crooked Beery, but when the pirates attack the steamer, she returns to Gable's side. A subplot involves the regeneration of ship's mate Lewis Stone, who has been cashiered out of the navy for cowardice and who redeems himself during the final battle. Based on a novel by Crosbie Garstin, China Seas is a programmer at heart, but is decked out with full A-picture trappings by MGM producer Irving Thalberg.