oad, the space-ship upon her rolling ways was
dragged out of the Hill and far out upon the level floor of the surface
before the tractors cast off and returned to the fortress.

"Everybody is under cover." Samms informed Rodebush. The chief was
staring intently into his plate, upon which was revealed the control
room of the untried super-ship. He heard Rodebush speak to Cleveland;
heard the observer's brief reply; saw the navigator throw his
switches--then the communicator plate went blank. Not the ordinary
blankness of a cut-off, but a peculiarly disquieting fading out into
darkness. And where the great space-ship had rested there was for an
instant nothing. Exactly nothing--a vacuum. Vessel, falsework, rollers,
trucks, the enormous steel I-beams of the tracks, even the deep-set
concrete piers and foundations and a vast hemisphere of the solid
ground; all had disappeared utterly and instantaneously. But almost as
suddenly as it had been formed the vacuum was filled by a cyclonic rush
of air. There was a detonation as of a hundred vicious thunderclaps made
one, and, through the howling, shrieking blasts of wind, there rained
down upon the valley, plain and metaled mountain a veritable avalanche
of debris: bent, twisted, and broken rails and beams, splintered
timbers, masses of concrete, and thousands of cubic yards of soil and
rock. For inertia and gravitation had not been neutralized at precisely
the same instant, and for a moment everything within the radius of
action of the iron-driven gravity nullifiers of the _Boise_ had
continued its absolute motion with inertia unimpaired. Then, left behind
immediately by the almost infinite velocity of the cruiser, all this
material had again become subject to all of Nature's everyday laws and
had crashed back to the ground.

"Could you hold your beam, Randolph?" Samm's voice cut sharply through
the daze of stupefaction which held spellbound most of the denizens of
the Hill. But all were not so held--no conceivable emergency could take
the attention of the chief ultra-wave operator from his instruments.

"No, sir," Radio Center shot back. "It faded out and I couldn't recover
it. I put everything I've got behind a tracer on that beam, but haven't
been able to lift a single needle off the pin."

"And no wreckage of the vessel itself," Samms went on, half audibly.
"Either they have succeeded far beyond their wildest hopes or else ...
more probably...." He fell silent and switche