High adventure as only Lin Carter can tell it!
Under the trackless sands of the Sahara lies Zanthodon. That vast subterranean realm is the final homeland of the one-time masters of the world's surface - great dinosaurs, mighty jungles, and the living bands of primitive peoples from Neanderthals to Ancient Minoans and even Barbary Pirates!
It was into the cruel hands of those feared corsairs that Eric Carstairs' beloved cave-maiden, Darya the Cro-Magnon princess, had fallen. It was his mission to save her, as well as to keep his caveman friends and his professor guide from the innumerable dangers spawned in the unmapped wilds of the Underground World
If JRR Tolkien was the single author most responsible for the existence of Fantasy as a modern publishing genre then the single editor and critic with the same claim was Lin Carter. His tireless advocacy of both modern fantasy writers and their historical forbears as the first editor on the Ballantine Adult Fantasy series was hugely influential.