hich I am familiar; but the
beings behind that red screen, whoever they are, have sources of power
as far above ours as ours are above those of the Solarians."

"How do you know?"

"That power, what is it?" "We have, then, the analyses of those fields
recorded!" Came simultaneous questions and explanations.

"Their power-source is very probably the intra-atomic energy of iron;
and if so, much remains to be done before I can proceed with my plan. I
must have the most powerful structure in the known Universe before I can
act. In the light of what I have just learned, the loss of the planetoid
is but a trifle." Roger, as unmoved as one of his own automatons, was
coldly analyzing the situation, thinking the thing through to its
logical conclusion, paying no attention whatever to the losses of life,
time and treasure now behind him.

"But what can you do about it?" growled the Russian.

"Many things. From the charts of the recorders we can compute their
fields of force, and from that point it is only a step to their method
of liberating the energy. We shall build robots. They shall build other
robots, who shall in turn construct another planetoid; one this time
that, wielding the theoretical maximum of power, will be suited to my
needs."

"And where will you build it? We are marked. Invisibility now is
useless. Triplanetary will find us, even if we take up an orbit beyond
that of Pluto!"

"We have already left your Solarian system far behind. We are going to
another system; one far enough removed so that the spy-rays of
Triplanetary will never find us, and yet one that we can reach in a
reasonable length of time with the energies at our command. Some fifteen
days will be required for the journey, however, and our quarters are
cramped. Therefore make places for yourselves wherever you can, and
lessen the tedium of those fifteen days by working upon whatever
problems are most pressing in your respective researches."

The gray monster fell silent, immersed in what thoughts no one knew, and
the scientists set out to obey his orders. Baxter, the British chemist,
followed Penrose, the lantern-jawed, saturnine American engineer and
inventor, as he made his way to the furthermost cubicle of the section.

"I say, Penrose, I'd like to ask you a couple of questions, if you don't
mind?"

"Go ahead. Ordinarily it's dangerous to be a cackling hen anywhere
around _him_, but he can't hear anything here now. His system is pretty