e, whatever it was, the darkness held no uncertainty.
He moved swiftly. His shrill shriek and the jerk of his arm both gave
evidence of his astonishment that his captive should walk so
blunderingly.

Then it seemed that he must have comprehended Rawson's blindness. A
green line of light passed close behind Dean's head. It was
cold--there was no radiant warmth--but, when it struck the face of a
wall of stone some twenty feet away, the solid rock turned instantly
to a mass of glowing yellow-red.

The cold green ray swung back and forth, leaving a path of radiant
rock behind it wherever it touched. And the rock was hot! Once the
green light held more than an instant in one place, and the rock
softened at its touch, then splashed and trickled down to make a fiery
pool.

* * * * *

Abruptly Rawson was able to see his surroundings. Also, he knew the
source of the red glow that had seemed like volcanic fires. There had
been others like his captor; they had been down below, and had played
their flames upon the rocks deep in the volcano. It was thus that they
made light.

With equal suddenness, and with terrible clearness, Dean found the
answer to one of his questions. He wrenched himself about to stare
behind him at the creature that held him in its grip. And, for the
first time, the wild experience became something more than an
unbelievable nightmare; in that one horrifying instant he knew it was
true.

Only a few minutes before, he had been walking across the cindery sand
of the crater top, walking under the stars and the dark desert
sky--Dean Rawson, mining engineer, in a sane, believable world. And
now...!

He squinted his eyes in the dim light to see more plainly the beastly
figure, more horrible for being so nearly human. He had seen them
briefly up above; the closer view of this one specimen of a strange
race was no more pleasing. For now he saw clearly the cruelty in the
face. It was there unmistakably, even though the face itself, under
less threatening circumstances, might have been a ludicrous caricature
of a man's.

Red and nearly naked, the creature stood upright, straps of metal
about its body. It was about Rawson's height; its round, staring eyes
were about level with his own, and each eye was centered in a circular
disk of whitish skin. The light went dim for a moment, and Dean,
staring in his turn, saw those other huge eyes enlarge, the white
covering of each drawing