A renowned paleontologist disappears while investigating a desolate swamp near a small town, where mysterious, gigantic tracks and lanes of crushed trees hint at an inexplicable force at work. His disappearance sets off a frenzy in the town, which soon witnesses the impossible: enormous, long-extinct dinosaurs—brontosaurs, tyrannosaurs, triceratops, stegosaurs, and pterodactyls—rushing through the streets. These prehistoric beasts, controlled by alien reptilian beings from a lost era, unleash destruction upon the modern world. The narrative follows the terrified witness, the paleontologist’s assistant, who becomes caught in the chaotic invasion. As he flees amidst burning buildings and panicking crowds, he encounters a horde of lizard-like creatures that ride upon these gigantic dinosaurs. These reptilian masters, remnants of a once-dominant Mesozoic civilization, had retreated underground when cataclysmic forces reshaped the earth. In their subterranean domain, they developed a vast, technologically advanced city lit by an eerie, perpetual crimson glow—a world maintained by a colossal, cyclically operating disk-platform that shuttles between the surface and an immense, molten cavern below. Within that cavern, the lizard-men had once ruled a sophisticated urban society, commanding their dinosaur steeds with sublime efficiency. They had harnessed the immense power of upward-thrusting, superheated air—channeled by a series of massive, engineered devices—to lift their disk-platform and transport their armies from their hidden realm to the vulnerable surface. Facing a new crisis as the molten fires from earth’s interior begin to threaten their underground existence, the lizard-men launch a final, devastating assault against the surface, intent on annihilating human civilization. As the assistant witnesses this dual-front horror—dinosaurs rampaging above and the grim mechanics of an ancient subterranean world below—the story evolves into a desperate struggle for survival. Amidst lethal encounters with lizard-men and frantic battles on the moving disk-platform, the assistant partners with the missing paleontologist, who resurfaces as a prisoner turned conspirator. They devise a risky plan to thwart the invaders by activating a switch designed by the lizard-men themselves. This mechanism would unleash a torrent of molten fire from the cavern’s depths, annihilating the invaders from within their own stronghold. In a climactic, relentless sequence, as dinosaurs and reptilian warriors threaten to overwhelm them, the two men engage in a battle on a descending metal platform. Through a combination of raw desperation and ingenuity, they manage to trigger the switch. The released inferno engulfs the disk-platform and the advancing forces, causing catastrophic structural collapses and halting the invasion—at least temporarily. The narrative closes on a scene of bleak aftermath: the town lies in smoldering ruins and the landscape is scarred by fire, yet the assistant, filled with a mix of despair and grim hope, stands alone at dawn. His silent reflection on the ruined city and the far-reaching consequences of this ancient terror underscores a central theme: the inexorable clash between forgotten, primeval forces and the fragile, emergent dominance of modern humanity.
By Edmond Hamilton · First published 1931 · Genre: Science Fiction, Space Opera, Pulp Fiction · 7 chapters