A remote valley hidden amid the towering peaks of the Andes and never before visited by civilized man is the scene of A.A. Merritt's classic novel of supernatural fantasy. The valley is inhabited by creatures long forgotten and races pledged to the resurrection of the glorious past.

Into this valley stumbles a young mining engineer, Nicholas Graydon. He defies the commands of the Snake-Mother's invisible but deadly servants and returns to the forbidden valley for the sake of Suarra, whom he loves. But Suarra can not be his until Graydon has persuaded the Snake-Mother to free the land of Yu-Atlanchi from Nimir, the Shadow of Evil. And the way to the Snake-Mother is beset with perils. Such as Lantlu, rider of dinosaurs; the Lizard men. And, of course, the Dark Lord himself.