walls, instead of being spherical, as you'd expect ... should think
they'd _have_ to radiate from a center, and so be spherical," Brandon
cogitated. "However, we've got nothing corkscrewy enough to go through
them, so we'll have to stand by. We'll stay inside whenever possible,
look on from outside when we must, but all the time picking up whatever
information we can. In the meantime, now that we've got our passengers,
old Doctor Westfall prescribes something that he says is good for what
ails us. Distance--lots of distance, straight out from the sun--and
I wouldn't wonder if we'd better take his prescription."

The two Terrestrial observers relapsed into silence, staring into
their visiray plates, searching throughout the enormous volume of one
of those great fortresses in another attempt to solve the mystery of the
generation and propagation of the incredible manifestations of energy
which they had just witnessed. Scarcely had the search begun, however,
when the visirays were again cut off sharply--the rapidly advancing main
fleet of the hexans had arrived and the scintillant Vorkulian screens
were again in place.

True to hexan nature, training and tradition, the fleet, hundreds
strong, rushed savagely to the attack. Above, below, and around the
far-flung cone the furious globes dashed, attacking every Vorkulian
craft viciously with every resource at their command; with every weapon
known to their diabolically destructive race. Planes of force stabbed
and slashed, concentrated beams of annihilation flared fiercely through
the reeking atmosphere, gigantic aerial bombs and torpedoes were hurled
with full radio control against the unwelcome visitor--with no effect.
Bound together in groups of seven by the mighty, pale-green bands of
force, the Vorkulian units sailed calmly northward, spiraling along with
not the slightest change in formation or velocity. The frightful planes
and beams of immeasurable power simply spent themselves harmlessly
against those sparklingly radiant green walls--seemingly as absorbent
to energy as a sponge is to water, since the eye could not detect any
change in the appearance of the screens, under even the fiercest blasts
of the hexan projectors. Bombs, torpedoes, and all material projectiles
were equally futile--they exploded harmlessly in the air far from their
objectives, or disappeared at the touch of one of those dark, dull-red
pressor rays. And swiftly, but calmly and methodically as at