Josiah Wakefield and his friend Dan Sturgis are buffalo hunters on the Northern Plains of Nebraska, shortly after the Civil War. Their job is to provide meat for the labourers pushing the Union Pacific Railroad relentlessly westward. Tiring of the bloody slaughter, they find work as trouble-shooters for the same railroad, as Sioux warriors are attacking the supply trains and tracklayers. However, the pair quickly discover that someone is supplying the Indians with repeating rifles, and that stolen 'Double Eagles' are the incentive. Recovering the gold turns out to be relatively simple: keeping hold of it is something else entirely. Even the Missouri River seems to be against them. Unsure who they can trust, they return to the railhead. Here, in a familiar environment, they decide to make a stand against all comers, in the hope that they can finally bring the ringleader to account.