Lobo Riler, one of the last of the mountain men, comes down from the Medicine Bow range to the town of Wild Horses on the Overland Trail, hoping to sell furs for supplies from his old friend Seth Topper.What he finds is a recipe for trouble -- a dozen rough and ruthless hide hunters led by a man named Kelleren and a pretty blonde prostitute named Rose working at the brothel called The Regret. Rose is the kind of woman that men want so badly they will fight and even die for her.And men do die, in a battle that spreads from the brothel into the street. Topper is one of those killed while Riler is gravely wounded. Kelleren and his crew ride out of Wild Horses with Rose as their captive. But they make one big mistake. If you shoot a mountain man you better make sure he's dead. Because if he isn't he will come for you -- all of you. Nothing -- not hell or high water or the United States army will keep Lobo Riler from a reckoning.