 Two deputies escorting a witness to the murder trial of a notorious gunslinger return to Norfolk with the news that the witness is dead, shot by an assassin who could not be seen. Lucas McCain, who is visiting Marshal Micah Torrance when he hears the news, tells Michah that he can aid the prosecution as he can place the gunslinger in the same location and time frame as the murder. As news of McCain s upcoming testimony spreads, a stranger arrives at the McCain ranch and nurses Mark s sick horse. In a scabbard on his horse is a high-powered sniper rifle with a 10x scope, the likes of which have not been seen since the Civil War. Who is the stranger and what does he want with Lucas McCain?