Charlotte looked at her Commander half understanding and half not.
Zhao Chen wore the look of one to whom it has all come clear of a sudden. "No wonder we could not find the Demon Race's starship works before.
"For they may have used certain topmost technologies of space.
"First of all, to set a stretch of space into a hidden state."
Charlotte understood something; she pointed at several of the pictures the T5 Phantasm-class Light Interstellar Stealth Scout Ship had taken and sent back. "This district that is closed off is very small; let alone the building of a starship works.
"Even the room wanted to build one great star gate would be hard to find there.
"And so it may be inferred that they have in high likelihood used dimensional-space technology, or folded-space technology.
"And by that a greater starship works may be hidden within the least compass of space; and so the likelihood of being found is lessened besides."
Zhao Chen nodded.
He raised a hand and opened a database, and drew several technical documents from it. "These are the reports of research upon folded space and dimensional space within the known universe at present.
"Dimensional space and folded space use somewhat different technologies, but their purpose is much the same.
"That is, to build outside the main space another small space.
"Only that to the present the several institutes of research within the universe face many hard problems; and even the Angel Race's institutes cannot to this day be certain of the steadiness of the small spaces they build.
"And if that small space be unsteady, there is at any moment the possibility of a spatial collapse; and the end of that is that the people and things within that small space will vanish forever, and no one will know whether they be dead or living, or whether they exist still.
"Or whether there be any possibility of return."
Zhao Chen, being a half-baked scientist — though what he chiefly holds in his mind is starship knowledge — has some understanding of other fields besides.
At his leisure Zhao Chen is not wholly a hands-off shopkeeper either; he keeps a close watch upon the several topmost technologies within the known universe.
"Then how are we to enter this small space?
"Nor do we know whether there be any restraint upon entering it; and if we go across and cannot come back, what then?
"And at present we have found but one thing that seems to be a small space.
"No one knows how many such small spaces the Demon Race has in the end," Charlotte said with some concern.
For after all they may guess at the rough quarter of it, but cannot come to know certain particulars.
The unknown is forever the most terrible thing.
Zhao Chen thought a while, pacing back and forth within the office.
All at once he halted, and fixed his eyes upon the Charlotte across the video window. "Is there anything upon where those Demon Race warships first appeared — at what star gates?
"And those interstellar transports that vanish mysteriously and appear mysteriously — by which star gates did they enter!"
"There is. All of it is recorded."
"Give me every record!" Zhao Chen said, his face set.
Very soon Zhao Chen had the whole of the records.
He looked at the three star gates marked upon the star chart, and beside them the numbers of Demon Race fighting warships that had welled up at that gate this while past.
And the places where interstellar transports entered star gates — and this part takes in above a dozen gates.
For they all connect to districts of interstellar resource production in every part of Demon Race territory.
Zhao Chen, reckoning up certain figures as he spoke, said, "We considered before tracing where these transports went, to determine where the Demon Race's starship works lie.
"But these transports all vanish once they enter a star gate loaded with raw material; and by the time they appear again, the raw material aboard is long since gone.
"Put this together with what we have guessed above.
"And it is that the Demon Race can build star gates within a small space!
"And these small-space gates can be joined to gates outside besides — which is why we simply cannot trace where those transports go!"
Charlotte stared with her mouth open; and some seconds later she looked in perplexity at those Demon Race warships on patrol within the pictures taken. "If it be so hidden, why should they set these patrolling warships here at all?
"Were it not for these suspicious warships, we should never have found this suspicious place."
"It may be that this is what they take for care and wariness." Zhao Chen halted of a sudden the fingers that had been moving without cease, and looked at the complicated star chart now showing before him.
Upon the chart, with those star gates for centers, there had appeared circle upon circle.
"Interstellar warships sail by star gate; and for the differing distances between gate and gate, the time wanted differs likewise — and by that a rough compass may be inferred.
"And upon this point the transports are the more convenient to reason from.
"For a transport must load and unload raw material besides; and the loading and unloading of raw material by transports of the same class is in the main much alike.
"And having these figures.
"We may shorten the compass of our search!" Zhao Chen's finger moved.
The star chart, which had been filled with circle upon circle like a child's scribbling, grew at a stroke a great deal cleaner, and there remained but some ten districts.
And these ten districts were divided, by their likelihood, into three colors: red, yellow and green.
"Charlotte, send at once as many of the interstellar stealth scouts in our hands as may be to these districts, to scout them as with a carpet — and above all to mark any anomalous fluctuation of space.
"And pass word to Zhao Wan'er's special fleet of interstellar stealth bombers: they may infiltrate Demon Race territory; and wherever a district is found that seems to be a Demon Race starship works.
"Let a certain number of stealth bombers be deployed about it and stand ready — but remember, do not beat the grass and startle the snake; wait upon our order!" Zhao Chen said gravely.
"Yes." Charlotte went at once to make the arrangements.
The video window closed.
Zhao Chen sat in his chair and let out a long breath, and there showed at the corner of his mouth the smile of a hunter who has found his quarry. "Three months and more I have sought you, and at last I have caught you by the horse's hoof.
"To strike a snake, strike it at the seven inches.
"When I have swept up these starship works of yours, let us see how much longer you can leap about.
"Opening war upon the Machine Race and the Angel Race at once.
"And by then I shall have your back courtyard afire besides.
"The Demon Race… it is time the weather changed for them too."
Zhao Chen shut his eyes and rested some minutes.
Then he raised a hand and put through a communication.
Very soon a familiar voice came from the other side.
"Commander, what are your instructions?"
"Chitong, pass word to those people of ours we have planted.
"Once the signal comes, they may act.
"Whether they can have their revenge, and get what they want, must rest upon themselves," Zhao Chen said with a light smile.
"Understood." Chitong took the order without a change of countenance, and passed it on.
And at this time, in every part of Demon Race territory, certain people amid their wine and their music, having received a short message, changed their look for the space of an instant — yet upon the face of it went on talking with the Demon Race nobles about them.
But a storm is about to sweep over the whole of Demon Race territory!