As a teenager, John McMasters won the Medal of Honor as a sniper for the Union Army during the Civil War.

Thirty years later, McMasters lives a peaceful life in the Arizona Territory, raising a family and running cattle. These days, he needs eyeglasses to hit a distant target. But that doesn't stop his wife and four children from buying him a special present for his fiftieth birthday: a beautiful new Remington shotgun. Turns out, he's going to need it... The Butcher gang has come to town. By the time McMasters learns of their arrival, they've invaded his ranch and slaughtered his family, hightailing it out of the county. McMasters wants revenge, using his new shotgun to hunt down those butchers like the animals they are. But he can't do it alone. His friend, Deputy U.S. Marshal Daniel Kirkpatrick, is hauling six of the deadliest criminals in the country to a prison in Yuma. They're cutthroat killers, every bit as ruthless as the Butchers.

But when McMasters points his Remington at their heads, they will become his killers...