maybe your suggestion isn't
as crazy as it sounds. We've got three or four days yet before either
side can send anything except on the sixth, so I'll find out what I can
do."

He flew at the task, and for the next three days could hardly be torn
from it for rest; but

"O. K., Mart," he finally announced. "They exist, all right, and I can
detect 'em. Look here," and he pointed to a tiny receiver, upon which a
small lamp flared in brilliant scarlet light.

"Are they sending them?"

"No, fortunately. They're coming from our bar. See, it shines blue when
I put a grounded shield between it and the bar, and stays blue when I
attach it to their detector ray."

"Can you direct them?"

"Not a chance in the world. That means a lifetime, probably many
lifetimes, of research, unless somebody uses a fairly complete pattern
of them close enough to this detector so that I can analyze it. 'Sa good
deal like calculus in that respect. It took thousands of years to get it
in the first place, but it's easy when somebody that already knows it
shows you how it goes."

"The Fenachrone learned to direct fifth-order rays so quickly, then, by
an analysis of our fifth-order projector there?"

"Our secondary projector, yes. They must have had some neutronium in
stock, too--but it would have been funny if they hadn't, at
that--they've had intra-atomic power for ages."

Silent and grim, he seated himself at the console, and for an hour he
wove an intricate pattern of forces upon the inexhaustible supply of
keys afforded by the ultra-projector before he once touched a plunger.

"What are you doing? I followed you for a few hundred steps, but could
go no farther."

"Merely a little safety-first stuff. In case they should send any real
pattern of sixth-order rays this set-up will analyze it, record the
complete analysis, throw out a screen against every frequency of the
pattern, throw on the molecular drive, and pull us back toward the
galaxy at full acceleration, while switching the frequency of our
carrier wave a thousand times a second, to keep them from shooting a hot
one through our open band. It'll do it all in about a millionth of a
second, too--I want to get us all back alive if possible! Hm--m. They've
shut off their ray--they know we've tapped onto it. Well, war's declared
now--we'll see what we can see."

Transferring the assembled beam to a plunger, he sent out a secondary
projector toward the Fenachrone vessel, as fast as i