Detective Strong is warned that an attempt will be made to free the crooks he is taking to the penitentiary. In spite of his vigilance, the prisoners escape when confederates start a gunfight on the train. Strong and his men scour the countryside for the fugitives. Helen, who has been warned, sees the convicts breaking into a box car. The girl gives the alarm, but before the detectives arrive, the crooks discover what has happened. Jumping from the car, the men overpower the crew of a locomotive, make them prisoners, and then start the engine down the track. Realizing that he and his pals cannot hope to make good their escape by remaining on the engine, Bud Carson abandons the locomotive at the river and starts it running wild back towards Lone Point. The runaway is seen by a road hand and word is flashed to Helen. Believing the engine crew to be bound and gagged aboard the iron monster, Helen decides against derailing it. Instead, she induces the man in charge of the wrecking derrick to run his apparatus on the parallel track. This done, Helen seizes hold of the boom hook and is swung out over the track upon which the runaway is approaching. Just as the wild engine flashes by, Helen drops from the hook, landing on the tender. Staggering into the cab, she brings the runaway to a halt just in time to save it from smashing into a chain of cars. Later, Helen accompanies Strong and his men in their chase after Bud /Carson's gang. The pursuit ends when the outlaws perish in the quicksands along the river.