ike a stage trick, the cavern was momentarily lit by a strong, orange yellow glare. Then the Winchester's report thundered and roared deafeningly; coincidentally arose a nerve-shattering scream. An exhalation, foul as a corpse long unburied, fanned his face. Terrified, he flattened to the rock wall as a huge, though dangerously agile body hurtled by with the speed of a runaway horse. Presently followed the sound of a ponderous fall, then a series of shrill, ear-piercing gibberings and squeakings, like those of a titanic rat—squeaks that rang like the chorus of Hell itself. Gradually they grew fainter, while in the darkness the heavy air of the tunnel became rank with the odor of clotting blood.
Nelson remained where he was, shaking like a frightened horse and bathed with a cold sweat.
"Wonder what it was?" he muttered numbly.
He broke off, for in the terrible darkness sounded a low but perfectly audible thud! thud! thud! thud!—and also the subtle noise of some rough surface rasping gently over the stone. His nerves crisped and shrieked for relief.
"It's coming again!" he told himself, and ejected the spent cartridge from the Winchester. "No use—it'll get me, but I may as well fight as long as I can."
Even stronger grew the musty smell of blood while that uncanny thud! thud! sound continued at regular intervals. Nelson waited, breath halted and finger on trigger, but still the darkness yielded no glimpse of those awful saucer-like eyes.
