minutes
until he circled, checked his wild flight, and sank slowly beneath the
lift of the dual fans to set the ship down as softly as a snowflake
beside a building that was dark and forbiddingly silent--a lonely
outpost in a lonely waste.

No answer came to his hail. The building was empty; the ship was gone.
And Chet! Chet Bullard!... Harkness' head was heavy on his shoulders;
his feet took him with hopeless, lagging steps to his waiting ship. He
was tired--and the long strain of the flight had been in vain. He was
suddenly certain of disaster. And Chet--Chet was up there at some
hitherto untouched height, battling with--what?

* * * * *

He broke into a stumbling run and drew himself within the little ship.
He was helpless; the ship was unarmed, even if the weapons of his
world were of use against this unknown terror; but he knew that he was
going up. He would find Chet if he could get within reach of his ship;
he would warn him.... He tried to tell himself that he might yet be in
time.

The little cruiser rose slowly under the lift of the fans; then he
opened the throttle and swept out in a parabolic curve that ended in a
vertical line. Straight up, the ship roared. It shot through a stratum
of clouds. The sun that was under the horizon shone redly now; it grew
to a fiery ball; the earth contracted; the markings that were
coastlines and mountains drew in upon themselves.

He passed the repelling area and felt the lift of its mysterious
force--the "R. A. Effect" that permitted the high-level flying of the
world. His speed increased. It would diminish again as the R. A.
Effect grew less. Record flights had been made to another ten
thousand.... He wondered what the ceiling would be for the ship
beneath him. He would soon learn....

He set his broadcast call for the number of Chet's ship. They had been
given an experimental license, and "E--L--29-X" the instrument was
flashing, "E--L--29-X." Above the heaviside layer that had throttled
the radio of earlier years, he knew that his call from so small an
instrument as this would be carried for hundreds of miles.

He reached the limit of his climb and was suddenly weightless,
floating aimlessly within the little room; the ship was falling, and
he was falling with it. His speed of descent built up to appalling
figures until his helicopters found air to take their thrust.

And still no answering word from Chet. The cruiser was climbing