Description

In the lawless border town of Klamath, the legendary scout Buffalo Bill is roused from sleep by a strange tapping at his door. Each morning he finds a letter pinned to the wood with a slender gold stick pin shaped like a skull and crossbones. The anonymous writer demands a meeting at a remote river bend—and warns that the matter is one of life and death. Suspicious of a trap, the scout nevertheless decides to answer the summons, accompanied by a loyal servant and an irrepressible Irish adventurer.

What begins as a rendezvous with a mysterious stranger quickly becomes a journey into the unknown. Following a treacherous canyon, the party plunges through a natural rock tunnel onto an underground river that carries them deep into a hidden valley. There they discover signs of a lost civilization, lurking enemies, and a beautiful woman in desperate peril. With danger at every turn, Buffalo Bill must rely on his frontier cunning and unerring courage to survive—and to uncover the secret behind the mysterious letters.