Fact1: residents of garrison at Fort Humboldt frontier outpost of United States Army are reported to be suffering from diphtheria epidemic, Fact2: special express train is heading up into remote mountain ranges towards fort filled with reinforcements and medical supplies, Fact3: epidemic at outpost is conspiracy between group of killers led by notorious outlaw Levi Calhoun, Fact4: train 's boxcars cargo transports large secret shipment of weapons rifles ammunition and dynamite stolen from U.S. arms manufacturers for sale in return for allowing Calhoun and men to mine and smuggle gold from lands, Fact5: Most of people on train including Governor Fairchild and Pearce are Calhoun 's partners in crime
Output: In the 1870s, residents of the garrison at the Fort Humboldt frontier outpost of the United States Army are reported to be suffering from a diphtheria epidemic. A special express train is heading up into the remote mountain ranges towards the fort filled with reinforcements and medical supplies. There are also civilian passengers on the train in the rear luxurious private car – Nevada Governor Fairchild Richard Crenna and his fiancee Marica Jill Ireland, the daughter of the forts commander. The train stops briefly in the small settlement whistle stop of Myrtle, where it takes on board local lawman United States Marshal Pearce Ben Johnson and his prisoner, John Deakin Charles Bronson, a supposedly notorious outlaw who was identified via a picture in a newspaper advertisement offering a 2,000 approximately 45,000 today reward. But as the journey goes on through the beautiful snowy mountain scenery, several train passengers, including most of the trains soldier escort, are mysteriously killed one by one or go missing. Deakin, who is actually an undercover U.S. Secret Service agent, discovers en route that the epidemic at the outpost is actually a conspiracy between a group of killers led by the notorious outlaw Levi Calhoun Robert Tessier, and a tribe of Indians under Chief White Hand Eddie Little Sky. Instead of medical supplies, the trains boxcars cargo transports a large secret shipment of weapons, rifles, ammunition and dynamite stolen from U.S. arms manufacturers for sale to the Indians, in return for allowing Calhoun and his men to mine and smuggle gold from their lands. Most of the people on the train, including Governor Fairchild and Marshal Pearce, are Calhouns partners in crime, and those innocents who discover the evidence for his sinister plot are one by one quickly mysteriously silenced. Eventually, Deakin narrows his list of possible uninvolved allies down to Marica, the Governors fiancee and Army Major Claremont Ed Lauter, who when finding out that Deakin is not quite what he seemed to originally be, agrees to assist the agent in his efforts to prevent the arms delivery. At snowcovered Breakheart Pass, all hell breaks loose as Indians attack the train to take the weapons they were promised, and Calhoun and his men ride out to the train in order to find out whats going on. Deakin and Major Claremont use dynamite to blow up and break the track rails, ground the train before it reaches the fort, and while Deakin runs interference, Claremont rushes ahead to Fort Humboldt to free the soldiers imprisoned by Calhouns gang. A gunfight breaks out when the freed soldiers led by their commander clash with the Indians and bandits at the train; Calhoun is killed by Gov. Fairchild when he threatens Marica, but the governor is then in turn cut down by Major Claremont. At the end of the battle, Deakin intercepts Marshal Pearce and shoots him when the corrupt lawman decides to go down fighting.