A pair of crooks steal a valuable package, hold up the crew of a freight engine, and compel the engineer to aid their escape. Learning this, Helen climbs into the cab of a locomotive standing on a siding and takes up the chase.

The smashed corner of a trunk containing counterfeiting paraphernalia reveals to Helen that there is treachery afoot at Lone Point. Detectives capture two of the trio, but one of them gets away, pursued by Helen, across a high railroad trestle. Seventh of the "Hazards of Helen" Railroad Series.

Helen receives a cypher message about a jewel robbery and trails the yeggmen to their lair. Discovered, Helen is bound and gagged and thrown into a box car, but gets loose, and leaps to the ground from the speeding train. The crooks are captured, Helen's pluck wins Billy's heart, but, as usual, she refuses, with an eye on next week's adventure.

Attempting to prevent an armed robbery in the paymaster's office, Helen is bound and gagged, and the thieves escape on a hand car. With her feet still bound by wire, Helen endeavors to pursue on foot, but stumbles and falls across the rails of the track of an oncoming train.

Brent, the night operator has been knocked unconscious by a piece of lumber projecting from a passing freight, and has been rendered temporarily insane. Meantime, a furious storm arises, a track walker discovers a washout and wires a warning to Helen, who sets the danger signal for the Limited which is due in ten minutes.

Helen catches two yeggmen who have broken into a freight car which has been detached from a train because of a hot box and are attempting to rifle the safe. The yeggmen escape aboard a passing freight with Helen, who has leaped upon the caboose, in hot pursuit, along with the trainmen.

Their demand for money having gone unheeded, Garibaldi and his gang wreck Number One. Howard, who attempts to interfere, is battered into insensibility. The criminals then place a note in the man's pocket warning the railroad officials to heed their demands in the future.

Fearing lest Cameron's horse beat the pony he has plunged on, Tony Dorgan orders one of his men to bribe the stableman to drug the animal. Saratoga Johnny tries to carry out Tony's order, but receives a beating at the hands of the irate Cameron employee.

Confronting Helen at the Lone Point Switch Tower, Denning and his pal imprison the girl in a clothes closet and then steal everything of value. In making their getaway, the crooks accidentally upset a lantern and set the tower afire. Helen, by picking the lock in the door with a hairpin, barely escapes death in the flames.

Hume and Frintz, while riding in a boxcar, see a trunk in the unguarded baggage car of a passenger train. By a daring leap from the freight to the passenger, Hume steals the trunk, throws it into one of the boxcars, and then leaps back. The trunk is missed and the loss reported from Helen's station.