Flandry was forced to whistle. “Where? Who?”
“Ever heard of Vixen? Well, I never had either before this. It’s a human-settled planet of an F6 star about a hundred light-years from Sol, somewhat north and clockwise of Aldebaran. Oddball world, but moderately successful as colonies go. You know that region is poor in systems of interest to humans, and very little explored. In effect, Vixen sits in the middle of a desert. Or does it? You’ll wonder when I tell you that a space fleet appeared several weeks ago and demanded that it yield to occupation. The ships were of exotic type, and the race crewing them can’t be identified. But some, at least, spoke pretty good Anglic.”
Flandry sat dead still. His mind threw up facts, so familiar as to be ridiculous, and yet they must now be considered again. The thing which had happened was without precedent.
An interstellar domain can have no definite borders; stars are scattered too thinly, their types too intermingled. And there are too many of them. In very crude approximation, the Terrestrial Empire was a sphere of some 400 light-years diameter, centered on Sol, and contained an estimated four million stars. But of these less than half had even been visited. A bare 100,000 were directly concerned with the Imperium, a few multiples of that number might have some shadowy contact and owe a theoretical allegiance. Consider a single planet; realize that it is a world, as big and varied and strange as this Terra ever was, with as many conflicting elements of race and language and culture among its natives; estimate how much government even one planet requires, and see how quickly a reign over many becomes impossibly huge. Then consider, too, how small a percentage of stars are of any use to a given species (too hot, too cold, too turbulent, too many companions) and, of those, how few will have even one planet where that species is reasonably safe. The Empire becomes tenuous indeed. And its inconceivable extent is still the merest speck in one outlying part of one spiral arm of one galaxy; among a hundred billion or more great suns, those known to any single world are the barest, tiniest handful.
However—attack that far within the sphere? No! Individual ships could sneak between the stars easily enough. But a war fleet could never come a hundred light-years inward from the farthest Imperial bases. The instantaneous “wake” of disturbed space-time, surging from so many vessels, would be certain of detection somewhere along the line. Therefore—
“Those ships were built within our sphere,” said Flandry slowly. “And not too many parsecs from Vixen.”
Fenross sneered. “Your genius dazzles me. As a matter of fact, though, they might have come further than usual, undetected, because so much of the Navy is out at Syrax now. Our interior posts are stripped, some completely deserted. I’ll agree the enemy must base within several parsecs of Vixen. But that doesn’t mean they live there. Their base might be a space station, a rogue planet, or something else we’ll never find; they could have sent their fleet to it a ship at a time, over a period of months.”
Flandry shook his head. “Supply lines. Having occupied Vixen, they’ll need to maintain their garrison till it’s self-sufficient. No, they have a home somewhere in the Imperial sphere, surely in the same quadrant. Which includes only about a million stars! Say, roughly, 100,000 possibilities, some never even catalogued. How many years would it take how many ships to check out 100,000 systems?”
“Yeh. And what would be happening meanwhile?”
“What has?”
“The Vixenites put up a fight. There’s a small naval base on their planet, unmanned at present, but enough of the civilian population knew how to make use of its arsenal. They got couriers away, of course, and Aldebaran Station sent what little help it could. When last heard from, Vixen was under siege. We’re dispatching a task force, but it’ll take time to get there. That wretched Syrax business ties our hands. Reports indicate the aliens haven’t overwhelming strength; we could send enough ships to make mesons of them. But if we withdrew that many from Syrax, they’d come back to find Merseia entrenched in the Cluster.”