Sterling and Ella steal a jewelry salesman's sample bag and make their getaway by boarding a passenger train. Word is flashed ahead to Helen, who in turn notifies Bowring, a railroad detective. The train is flagged.

Learning that the driver of the Comet car has been disabled on the eve of the big race, Sinton, a gambler, bets heavily on its rival. But his plans go awry when Gordon, the owner of the Comet car, meets Naroche, a celebrated French driver, and engages him to pilot the racer.

Helen, by a courageous leap from a motorcycle, reaches the burning boxcar in which the detectives are imprisoned and succeeds in applying the brakes in time to bring it to a stop and save them from almost certain death.