Registered trotting horse Jolly Roger is thrown out of racing for speeding into a gallop whenever he races. Bought by Captain Martin Hanley of the Boston Police Force, Jolly Roger manages to redeem himself by helping Captain Hanley save a man at a race track. The story makes the news and his former owner and trainer, Pam Churchill purchases Jolly with the hope of racing again. With his new found discipline, Jolly Roger becomes a champion.