at 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.

* * * * *

Emboldened, he stooped and, jerking off his left glove, commenced to
grope among the boulders. Somewhere near at his feet the flashlight
must be lying. Hoping against hope that its fall had not shattered the
bulb, he ran his fingers over the cold, damp stones, every instant
expecting to feel the clutch of the unseen monster. How tiny, how puny
he was! All at once his fingers encountered the smooth familiar shape
of the flash and he raised it cautiously through the darkness.
Patiently he shifted the Winchester to his left hand in order to set
the flashlight on the top of a flat rock, pointing it as nearly as he
could determine in the direction from whence came those ominous,
stealthy sounds.

"Guess I'll switch on the light," he decided, "and trust to drop
whatever it is before it reaches me."

Taking a fresh grip on his quivering nerves, Nelson cautiously cocked
the .38-55, cuddled the familiar stock to his shoulder. He sighted,
then with his right hand pushed down the catch lever of the
flashlight.

Instantly a dazzling white beam shot forth to shatter the gloom. The
hair on the back of Nelson's hands itched unbearably, while the cold
fingers of madness clutched at his brain, for the sight which met his
eyes all but bereft him of his wavering sanity. There, belly up,
across a low ridge of basalt, lay a hideous reptile, which in form
faintly resembled an enormous and fantastic kangaroo. Its scabby belly
was of the unhealthy yellow of a grub, a hue whi