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.
Billy Warren, timekeeper on the construction job, arouses the enmity of Brent and Easton when he resents their bullying of the other men. Pay day finds the men celebrating in riotous fashion, and Brent in a crazed moment breaks into the station and attacks Helen. Her cries bring Warren, who trounces the bully.
Brandt, a defaulting cashier, hiding in Lone Point in his effort to throw detectives off his track, cuts the wires of Helen's telephone to prevent her from calling for help, binds and gags her, and boards the outgoing Limited. Freed by Detective Sheridan, the two of them get into a gasoline speeder standing on the sidetrack and pursue the Limited.
Blake, a quarrelsome lineman, and a widower with two daughters, is in love with Helen, but she rejects his advances. Helen spies Myra, Blake's three year old daughter, who has ventured onto the tracks of the oncoming Elwood Express, and just in the nick of time, grasps the girl off the tracks, but in so doing, must leap off a trestle into a river thirty feet below
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.
Claim jumper Dave Marco and his boss Earl Foster, a crooked investment broker, hire chemist Ralph Brandon to falsify papers that a certain worthless mine is valuable then convince Ralph's mother to invest all her money in the mine. Ralph’s sister Holly meets Jack Mason, whose mine is actually valuable though not yet profitable, and they fall for each other. Once Mrs. Brandon finds out she has been duped, though forced into silence by the threat of having Ralph’s malfeasance exposed, and Marco attempts to jump Jack’s claim events come to a head until the happy conclusion.
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.
When Dick, an aeronaut is wrongly accused of shooting Dan, a trouble-making, quarrelsome cowboy, Helen aids his escape on the outgoing Black Diamond Express.
Disguised as baggage man, Burgess and Whelan board the train to which is coupled the special carrying Nina Mallotte and her theatrical troupe. The thieves plan to steal the actress' gems.
Communicating with his pals outside, Daly informs them as to the date upon which he is to be taken from the jail to State's prison. Kling, the head of the gang, arranges to hold up the train carrying Daly and effect the man's rescue.
Tony, a half-breed Mexican is kicked from pillar to post, but he grasps a chance for revenge on society when he peers through the station window and sees Helen, the operator at Lone Point, opening the express company bag containing a valuable shipment to a local rancher.
Apparent carelessness causes Conductor Lawton and his train crew to be laid off for thirty days. A gang of car thieves, pursued by police, jump aboard a freight, and after a stiff combat, succeed in throwing the crew off the speeding train to the ground.
Steve Nelson, a clever crook, arrives at the little station where Helen is operator. He lives quietly at the village's little boarding house preparing for a coup when Helen receives instructions that lead her to suspect Steve.
A college boy's prank imperils the life of the railroad president's son who has worked his way up to engineer in his course that starts "from the bottom." Tied to the engine, the son is speeding on a runaway engine toward the Flicker Creek bridge which has been swept away by the floods.
Down and out, Bob, an engineer, drifts into town. His condition excites Helen's sympathy. Using her influence, the girl secures him a position with the railroad. Rankin, Dalmore and Dougherty escape from prison. The men attempt to enter the Hobart Tower, but Helen, seizing a revolver, baffles them.
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.
Chilton, a crooked dealer in antiques, decides on a daring scheme to recoup his finances by defrauding the railroad. A car-load of cheap furniture is shipped with a valuation of $40,000 on it. Blanding, the tool of Chilton and his partner, awaits at Lone Point a telegram giving the number of the car.
In the second entry of the popular Hazards of Helen series, Helen, is temporarily assigned as a telegraph operator at Quarry Depot; bad blood springs up between two men who are seeking Helen's favor, but to whom she has remained impartial.
Helen, the telegrapher at Downing Junction, receives word that an engineer has been accidentally shot by a partridge hunter, and the runaway train will collide with the Eastbound Express. Helen jumps onto a nearby standing locomotive, opens it up full throttle, catches up the Express, warns the engineer of the impending danger
Following the wreck of the pay-car, it is rifled by a band of conspirators. All but one of the band later succeed in making their escape from the town by automobile, but this one is forced to jump aboard a freight train to which is attached the wreck train and huge crane.