In this unique Western tale from the legendary author of The Untamed, a man sent to spy on an isolated mountain ranch finds dangers of a mysterious kind. Alaskan mail carrier Lefty Bill Ranger has faced plenty of risk on his appointed rounds. But now he’s confronting a new kind of danger. One of the most feared men in the territory is offering him a job. Ranger must go deep into the Sierra Mountains where Peter Crosson and his son live in total isolation. For six months, Ranger is to watch them and report what he sees. The pay for this espionage will be $6,000 in gold—an amount Ranger can’t refuse. Pretending to be a trapper, Ranger sets up camp and keeps a close eye on the Crosson ranch. But soon he witnesses events he can barely describe: a gigantic mountain lion is pursued by a pack of wolves that appears to be controlled by a youth on horseback. Later, two outlaws enter the Crosson ranch armed to the teeth—only to disappear. When Ranger next sees them next, the men are fleeing for their lives, covered with wounds. Whatever is happening on the Crosson ranch is unlike anything Ranger has encountered before. But things start to become clear when he experiences what they call the lightning of gold . . .