an
airlock in working order, and were soon in the second lifeboat, where
Stevens hastily turned on a communicator and peered out into space.

"There they are! There's another stranger out there, too. They're
fighting with her, now--that's probably why they didn't polish us off."
Steel-braced, clumsy helmets touching, the two Terrestrials stared
spell-bound into the plate; watching while the insensately vicious
intelligences within the sphere brought its every force to bear upon
another and larger sphere which was now so close as to be plainly
visible. Like a gigantic drop of quicksilver this second globe
appeared--its smooth and highly-polished surface one enormous, perfect,
spherical mirror. Watching tensely, they saw flash out that frightful
plane of seething energy, with the effects of which they were all too
familiar, and saw it strike full upon the dazzling ball.

"This is awful, ace!" Stevens groaned. "They haven't got ray-screens,
either, and without them they don't stand a chance. No possible
substance can stand up under that beam. When they get done and turn back
to us, we'll have to dive back to where we were."

* * * * *

But that brilliant mirror was not as vulnerable as Stevens had supposed.
The plane of force struck and clung, but could not penetrate it. Broken
up into myriads of scintillating crystals of light, intersecting,
multi-colored rays, and cascading flares of sparkling energy, the beam
was reflected, thrown back, hurled away on all sides into space in
coruscating, blinding torrents. And neither was the monster globe
inoffensive. The straining watchers saw a port open suddenly, emit a
flame-erupting something, and close as rapidly as it had opened. That
something was a projectile, its propelling rockets fiercely aflame; as
smoothly brilliant as its mother-ship and seemingly as impervious to the
lethal beams of the common foe. Detected almost instantly as it was, it
received the full power of the savage attack. The hitherto irresistible
plane of force beat upon it; ultra-violet, infra-red, and heat rays
enveloped it; there were hurled against it all the forces known to the
scientific minds within that fiendishly destructive sphere.

Finally, only a scant few hundreds of yards from its goal, the
protective mirror was punctured and the freight of high explosive let
go, with a silent, but nevertheless terrific, detonation. But now
another torpedo was on its way, an