Billy Kirk and Burt Haslam are two deputy US marshals, who are riding into Pine City as undercover cowpokes to investigate the trouble heating up in the county.
As they near the territory they interrupt a robbery attempt on a stage coach and after a short scuffle of gunshots, the ambushers are scared off.
But the trouble doesn’t stop there, they are only just settling into a hotel room in Pine City when Francis Calver, the most powerful ranch owner in the county, comes riding in with his Thunder Canyon crew.
He claims that Ben Tulk’s men have shot up his spread, whilst Tulk in turn accuses Calver of butchering his cattle.
Meanwhile, Haslam and Kirk wonder if there is a third party causing all the strife to suit his own ends.
Eventually they find the root of the trouble but before they can bring it to an end, much blood will be spilt as the whole range echoes to murderous gunfire.