With a little help from his old gang, widely known outlaw Jud Starr slips the hangman's noose and begins a law breaking rampage over the entire Cimarron Strip. Upon discovering that Starr and his gang are using the Cherokee Outlet as a place of refuge, Marshal Crown sets out to track them down.

With Marshal Crown out of town, acting Deputy Marshal MacGregor pursues escaped hired gunman Luther Happ. After tracking down the escaped fugitive and killing him in a shootout, the wounded MacGregor passes out and awakens in a Texas jail, where he is accused by Sheriff Jack Hawkes of murdering Deputy Luther Happ.

Marshal Crown tries to prevent the Houston clan from entering the Mocane Valley before it's open for settlement. The Houston's believe they'll have little competition for prime land because of the legend of a malevolent beast thought to lurk in the valley. When the wagon train is destroyed and most of its travelers killed, Marshal Crown and his men search for the culprits not knowing if their quarry is man or beast.