medium height. His deep-sunken eyes were those of a
dreamer, a searcher. They were the eyes of a man who had seen strange
and startling things. At present they were staring into the pulsing
wave of humanity flowing northward on the endless steel bands beyond
the platform.

Quite suddenly they lighted with pleasure as a man and a girl detached
themselves from the swift moving river of people and hurried to the
spot where he stood.

"Think we were never coming?" Karl Danzig's eyes were much like those
of Aaron Carruthers. Just now they sparkled with suppressed
excitement.

Aaron Carruthers smiled in turn. "No, Karl. Any man but you. I
couldn't imagine you being late." He turned his attention to the slim,
dark haired girl. "Nanette," he murmured, extending his hand, "I
didn't think you'd come."

Dazzling white teeth caught the glow of the blue-white incandescents
along the platform, and became under the bow of her red lips a string
of priceless pearls.

"I had to come, Aaron. Karl has done nothing but talk of your amazing
discovery. The experiment fairly frightens me at times especially when
I recall the sad fate of your friend, the missing Professor Dahlgren.
I wish you boys would give up the idea--"

"Nan, be still," broke in Karl, with brotherly rudeness. Turning to
Carruthers. "Everything all ready, Aaron?" he asked.

* * * * *

Carruthers nodded. "As far as humanly possible. The element of error
is always present. I've checked and re-checked my calculations. I've
augmented the vacuum tubes by installing three super-dimensional
inverse power tubes." He clasped the girl's arm. "The street is no
place to talk. Let's go to the laboratory."

They crossed the moving bands by an overhead bridge and cut down a
narrow canyon to the entrance of a crosstown series of bands. They
stepped onto the first band. The speed was moderate. From there they
moved over to the second. Carruthers was in a hurry. He guided the
girl and her brother across the third to the fourth band of moving
steel.

Buildings slid past them like wraiths in the electric light. They felt
no winter chill, for the streets and platforms were heated by a
constant flow of warm air from slots ingeniously arranged in the band
of swift moving metal upon which they stood. Within a few minutes they
had arrived at their destination. Quickly they reversed their path
across the moving bands until they reached the disembarking pl