Jared Macalester is, to all appearances, a trackwalker for the Union Pacific. His first notable action in this entertaining Western pot-boiler is to throw a boorish cowboy off a train, while the train is in motion. Before Macalaster can show his face in the tale, bandits rob a UP train of its money shipment, and kill an agent. Macalester has, in fact, been assigned by the Faraday Security Agency to solve the robbery case, and uses the trackwalker position as a cover. His assignment evolves to cleaning up the railroad town of Ironsprings, and is complicated by the corrupt local lawmen and various roughnecks.