Caspak

When adventurer Bowen Tyler is taken aboard an enemy submarine, he never dreams that his voyage will end in a land where time itself is prisoner. But in the uncharted seas at the bottom of the world, Tyler and the crew of the U-33 discover the mysterious forgotten continent of Caspak, where the savage denizens of a thousand lost ages roam vast primeval jungles.

Bowen Tyler, his reluctant crew and a blonde heroine, find themselves marooned in a nightmare world of mighty dinosaurs and bestial apemen who kill on sight. This is the lost continent of Caspak, a hot, dark and mysterious prehistoric world located somewhere in the icy waters of the Antarctic. Their only hope of rescue is a note in a bottle flung into the sea. The survivors persist and penetrate the heart of Caspak to find the incredible secret that claws, fangs and spears have guarded since the beginning of time.

In uncharted Caprona, a continent lost from the map of the earth, where time had stopped and all the primeval creatures of long-gone ages still prowled, Bowen Tyler was lost. To find Tyler, Thomas Billings traveled across the world to Caprona, with all the weaponry the modern world afforded. A light hydroplane would allow him to scale the perilous wall of cliffs that surrounded the island and rifles, pistols, and ammunition would provide protection against the monstrous prehistoric beings Tyler had so vividly described. But even stranger mysteries awaited him where that barbaric civilization hid, torn between the impassable jungle on the one side and an unknown menace on the other.

On Caprona, the Land that Time Forgot, all of the world's savage past still lived. Here were dinosaurs and flying reptiles, here were the most primitive of cavemen, and the last of the Bronze Age barbarians. But there was one more secret that the claws and fangs and sharp-edged spears guarded most of all. This is the story of the man who tried to find that final secret. When Bradley, the adventurer, dared to cross the last terrible barrier to the heart of Caprona, he entered a world of wonder, terror and danger beyond the imagination of any man—except Edgar Rice Burroughs.