Piracy and mutiny and other major crimes of the sea are the themes of this nautical melodrama, with a locale of the China Seas and an abundance of action. Harley is captain of a tramp steamer engaged in the precarious business of smuggling pearls across the China Seas. This state of affairs brings him into contact with a mutiny aboard. His crew mutinies to get the pearls and both crew and passengers are captured by a sea raider. Through subterfuge, and with the aid of a woman passenger with whom the captain is in love, he outwits the pirate and is successful in saving the pearls, his passengers and crew.