Boston, California, China and the seas between are the settings for a China Trade adventure that exposes crooked dealings, clears up a rivalry between brothers, and a future for 18 year old John Lincoln of Cohasset. Back from his first run as captain of a small ship, John is forced by circumstances to sign on the Sea King, as an ordinary sailor. But meanwhile, John's brother Fred has made a deal with Meivin Richards, the first mate, to ""fix"" a race between the Sea King and another ship so the Sea King will lose. But on the runs, the treachery is discovered. Fred's conscience suffers a reversal and as he helps John brand the culprits, both boys are given good opportunities by their employers.