Using an old cannon that once belonged to Napoleon's army, an outlaw gang has been bringing trains to a halt and then robbing them. Now Edward Sheffield--one of the owners of the railroad--wants to hire Conrad Morgan, known as The Loner, to wipe the gang off the map. The Loner isn't interested, especially when Sheffield's hot-blooded wife tries to seduce him into going after the gang's leader, Gideon Black--a renegade ex-colonel-turned-outlaw. But when the gang turns their big gun on a town, killing several innocent people, The Loner has to choose sides. The best way to take them out? Become one of them. And that's when The Loner uncovers some unsavory secrets--and finds himself caught between the middle of two ruthless forces...