ever. Here, too, they saw
the first sign of active life in the valley: a flight of giant
dragonflies skimming over the water. The insects took fright as soon as
Honath showed himself, but quickly came back, their nearly non-existent
brains already convinced that there had always been men in the valley.

The roar got louder very rapidly. When the three rounded the long,
gentle turn which had cut off their view from the exit, the source of
the roar came into view. It was a sheet of falling water as tall as the
depth of the gorge itself, which came arcing out from between two
pillars of basalt and fell to a roiling, frothing pool.

"This is as far as we go!" Alaskon said, shouting to make himself heard
over the tumult. "We'll never be able to get up these walls!"

Stunned, Honath looked from side to side. What Alaskon had said was all
too obviously true. The gorge evidently had begun life as a layer of
soft, partly soluble stone in the cliffs, tilted upright by some
volcanic upheaval, and then worn completely away by the rushing stream.
Both cliff faces were of the harder rock, and were sheer and as smooth
as if they had been polished by hand. Here and there a network of tough
vines had begun to climb them, but nowhere did such a network even come
close to reaching the top.

Honath turned and looked once more at the great arc of water and spray.
If there were only some way to prevent their being forced to retrace
their steps--

Abruptly, over the riot of the falls, there was a piercing, hissing
shriek. Echoes picked it up and sounded it again and again, all the way
up the battlements of the cliffs. Honath sprang straight up in the air
and came down trembling, facing away from the pool.

At first he could see nothing. Then, down at the open end of the turn,
there was a huge flurry of motion.

A second later, a two-legged, blue-green reptile half as tall as the
gorge itself came around the turn in a single bound and lunged violently
into the far wall of the valley. It stopped as if momentarily stunned,
and the great grinning head turned toward them a face of sinister and
furious idiocy.

[Illustration] [2]

The shriek set the air to boiling again. Balancing itself with its heavy
tail, the beast lowered its head and looked redly toward the falls.

The owner of the robbed nest had come home. They had met a demon of Hell
at last.

* * * * *

Honath's mind at that instant went as whi