nsively, then with growing boldness and curiosity.

"This is the control room!" exclaimed Clee suddenly; and after a
moment Jim agreed with him. It was the simplicity of the controls
which had prevented them from recognizing it at first. Against the
left wall was a great table with a tilted top, bearing, in its center,
a raised and hooded eyepiece giving a view into a large, enclosed
black box. On each side were several rows of small, shiny, metallic
levers and what they took to be instrument dials--round, cup-shaped
depressions with pointers free to move across dials lined with
disorderly and meaningless convolutions. For the full length of the
middle wall, straight ahead, was a broad table of some jet-black
polished material, and on it was a large array of instruments and
apparatus, all unfamiliar to them. Against the draperies of the wall
to their right was one large cushioned chair, simple and beautiful in
its lines.

No living person or thing could be discerned in either the main room
or the alcove.

For several minutes the two men walked all about, examining everything
they saw with curiosity and interest; and then Clee discovered a
peculiar thing. His watch-dial, glowing very brightly now, would
perceptibly increase in brilliance every time he neared the great
chair. With sudden inspiration he took out his package of tobacco and
held it in the line his watch made with the chair--and he found that
his watch stopped glowing. He tried it again from another angle, and
the result was the same. From that chair came the electrical
disturbance that was making his watch-dial glow--yet nowhere near the
chair was any bit of electrical apparatus to be seen.

What he did see in the chair, though, almost caused his heart to stop
beating. The cushions of the seat, compressed before, began to puff
out to full volume, as if someone had just risen from them. And then,
faintly but sharply outlined in the long-napped rug in front, appeared
the print of a human shoe!

"A man!" breathed Clee. "A human being!"

* * * * *

The two men stood frozen in their tracks. Clee's arm, with the package
of tobacco in his hand, was still outstretched toward the great chair,
but now the dial of his watch was glowing brightly again. Something
within caused him in spite of his terror to move the package between
the watch and the space above the footprint on the rug. The glowing
stopped. The man--devil--whatever