John Stockbridge was once a peaceful man of medicine. Now, he's better known as Dr. Vengeance, a man who is as fast with a shotgun as any other gunfighter is with a six-gun. The murders of his wife and child left him with an aching hole where his soul once was. His only solace comes from wandering the West, where he encounters a woman and her two children searching for her missing husband. While helping search for the missing trapper, Stockbridge must take down a bunch of vicious highwaymen one by one.