Josiah Wakefield and his friend Dan Sturgis find work as troubleshooters for the Union Pacific Railroad. The pair discover that someone is supplying Sioux warriors with repeating rifles, and that stolen 'Double Eagles' are the incentive. Recovering the gold turns out to be simple: keeping hold of it is something else entirely. Unsure who they can trust, they return to the railhead. Here, they make a stand against all comers, in the hope that they can finally bring the ringleader to account.
