began herding him toward a far back corner of the big cavern.

Stopping a few yards away from the edge of what seemed to be a wide
deep pit in the rock floor, the guard stripped Powell's bonds from
him. Powell made no move to take advantage of his freedom, realizing
that the swarming thousands of rodents in the cave made escape out
of the question for the moment. He allowed himself to be docilely
herded on to the edge of the pit.

And the next moment he exclaimed aloud in delighted surprise as he
gazed down at the floor of the pit ten feet beneath him. There,
sitting on a low heap of stones on the pit's sandy floor,
white-faced and weary but apparently unhurt, was Joan Marlowe.

* * * * *

The girl's face brightened in relief as she looked up and recognized
him.

"Larry! Oh, thank God you've come!"

The leader of the guards motioned for Powell to jump down into the
pit. He needed no urging. A moment later he landed lightly on the
sandy floor of the pit, and Joan was in his arms.

The rat-men left a dozen of their number scattered as sentries
around the edge of the pit. The rest of them returned to the main
horde, leaving the prisoners to their own devices.

"I knew that you'd come, Larry, as soon as you got my note," Joan
exclaimed happily. "But how did you ever succeed in finding this
Cave of Blue Flame?"

"I didn't find it myself," Powell admitted. "I was captured like a
boob and dragged here." He told Joan of his mishaps since arriving
in Arret.

The girl nodded when he had finished. "Much the same happened to me,
Larry, only the red moon wasn't shining then. The only light was
from what looked like the dim ghost of a big yellow sun. I
materialized in Arret almost in the middle of a scouting group of
rat-men. They took me captive immediately. When several minutes
passed without you and Uncle Benjamin broadcasting the recall wave
for me, I knew that something terrible must have happened back in
the laboratory, and that I might be marooned in Arret for hours.

"I tried to hang onto my Silver Belt, of course," the girl
continued, "but when I was brought to the cavern here I saw that the
king was going to take it. There was a notebook and a pencil in my
laboratory smock. I managed to write the note and twine it into the
belt just before it was taken from me. The king seemed to think the
note enhanced the Belt's value as an ornament. He was wearing it
when I last saw it. Was