The Lincoln County Wars are over. Billy Bonney—"The Scourge of the Midwest"—and his band of Regulators have lost, and are on the run. When a job offer to "hunt a big cat" menacing a mining operation in the small bordertown of Tascosa, Texas, comes their way, it seems like the perfect chance to flee the law and earn a big stake. Maybe a big enough stake for everyone to make a clean break and go straight for good.

It's not a big cat killing the miners in Tascosa, however. It's something ancient and evil, with an unquenchable thirst for human flesh. Even worse, Billy and his pals find themselves in the midst of one man's obsessive search for the Lazarus Stone, a mythical gem purported to possess uncanny healing powers. According to legend, the last knight of the Templars hid the stone in Cottonwood Mountain, just outside Tascosa. The mining operation was nothing but a sham to find the stone; because Wagner Rutherford III—a wealthy plantation owner and amateur archeologist—believes the stone can resurrect his dead son. Even more—the monsters are drawn to the stone's power like moths to a flame, and stand between them and the stone.

Since the end of the Lincoln County Wars, Billy the Kid has been without purpose. A gun pointed nowhere. Now, with the help of a former priest-turned occult scholar, a small town sheriff, and itinerant and adventuring frontier doctor, Billy the Kid will find his new purpose—and destiny—or he'll finally feel the taste of death on his tongue.