vations of our pursuer will, of course, be
necessary to decide that point. It would be useless to go to Titan,
for they would be powerless to help us. We could not hold their mirror
upon either the _Sirius_ or their torpedoes against such forces as that
fortress has at her command. Then, too, we might well be bringing down
upon them an enemy who would destroy much of their world before he could
be stopped. Both Uranus and Neptune are approximately upon our present
course. Do the Titanians know anything of either of them, Steve?"

"Not a thing," the computer replied. "They can't get nearly as far as
Uranus on their power beam--it's all they can do to make Jupiter. They
seem to think, though, that one or more of the satellites of Uranus or
Neptune may be inhabited by beings similar to themselves, only perhaps
even more so. But considering the difference between what we found on
the Jovian satellites and on Titan, I'd say that anything might be out
there--on Uranus, Neptune, their satellites, or anywhere else."

"Cancel Uranus, and double that for Neptune," Brandon commanded.
"Realize how far away they are?"

"That's right, too," agreed Stevens. "Before we got there, with any
acceleration we can use now, this whole mess will be cleaned up, one way
or the other."

* * * * *

Westfall completed the series of observations and calculated his
results. Then, with a grave face, he went to consult the medical
officers. The women, children, and the two Martian scientists were sent
to the sick-bay and the acceleration was raised slowly to twenty meters
per second per second, above which point the physicians declared they
should not go unless it became absolutely necessary. Then the scientists
met again--met without Alcantro and Fedanzo, who lay helpless upon
narrow hospital bunks, unable even to lift their massive arms.

While Westfall made another series of precise measurements of the
super-dreadnought of space so earnestly pursuing them, Brandon stumbled
heavily about the room, hands jammed deep into pockets, eyes unseeing
emitting clouds of smoke from his villainously reeking pipe. The
Venetians, lacking Brandon's physical strength and by nature quieter of
disposition, sat motionless; keen minds hard at work. Stevens sat at the
calculating machine, absently setting up and knocking down weird and
meaningless integrals, while he also concentrated upon the problem
before them.

"They are still