While taking a steamer to Los Angeles, Charlie Chan (Warner Oland) and his number one son Lee (Keye Luke) they meet up with a famous horse breeder. But before a true friendship can be made, the man is killed. The ship authorities believe that the stallion the man was taking to the Santa Anita racetrack kicked him to death. But Charlie discovers that he was murdered. There is a gang of criminals who are set on fixing the race and they want their horse to win. After they dock in Los Angeles, Charlie and Lee set out to discover the true identity of the boss behind the gambling ring but they are kidnapped. When they manage to escape, the race has already started. Will the gamblers make a big payoff or will all of their efforts be for nothing?