ed, melting swiftly until only a diamond-encrusted skeleton
was left. The color of the great Devil Crystal began to gleam pink
as the victim's flesh and blood were absorbed.

The egg-like excrescence under the nucleus turned in hue to pale
translucent amber in whose depths the diamond skeleton gleamed with
weird brilliance. Then there came a sudden twang, as of a violently
plucked string on a bass viol, and the amber egg dropped from the
faceted side. The Crystal's feast was over.

One of the most terrifying aspects of the whole thing had been its
incredible speed. The entire tragedy had occurred in but little over
two minutes from the time the lance-arm had first struck the
rat-man.

In the meantime the body of the second rodent had been drawn in and
devoured by another of the carnivorous crystalline monsters. There
came a second twang now, as its skeleton in its amber shroud was
discarded.

* * * * *

Powell's brain reeled as he saw the other crystals move sluggishly
nearer the foot of the rocky projection in anticipation of the next
victims.

The remaining two captive rat-men came next. They were swiftly
drugged, unbound, and started on their dazed march. They trudged
woodenly out the rocky projection to its end, then on and over; and
again the grim tragedy of the Devil Crystal's feast was repeated, to
the accompaniment of that eerily beautiful crashing, tinkling song.

The four Devil Crystals that had completed their gruesome feast
moved sluggishly away, leaving the space clear for the two crystals
that remained unfed. The score of guards closed in upon Joan and
Powell.

With the crystalline doom at last staring them squarely in the face,
Powell went berserk in a final desperate effort to gain even a
moment's respite. He lashed out in a writhing, kicking flurry that
almost cleared the space around them.

Then three of the rat-men slipped behind him, and a second later his
feet were jerked from under him. His bound arms made him helpless to
avert his fall, and he crashed heavily to the ground. Then a dozen
of the powerful little beasts swarmed over him, completely
overpowering him by their numbers.

Claw-like hands pried his set jaws apart. A cup of the cloudy white
liquid was pressed to his lips. He choked; then, unable to help
himself, he had to let the stuff pour down his throat. It had an
acid taste faintly reminiscent of lemons. The rat-men apparently
wanted to make