“This can’t be coincidence,” Oscar said; he sounded shocked, even a little frightened. “It’s been there for over a thousand years, and then it vanishes just as we come along? No way. No goddamn way. Something knows we’re here.”
The bridge crew were looking around anxiously, seeking reassurance from one another. Wilson had been thinking along similar lines himself; quite a loud voice in his head was urging him to run. And don’t look back. The starfield was beginning to reappear around the edges of the barrier as light swept in toward the Second Chance. It gave the rather unfortunate impression of a giant mantrap opening its jaws.
Wilson turned to Tunde. “What’s the Dark Fortress doing?”
The physics section went into a fevered huddle over their consoles, running analysis routines over the hysradar scans. Wilson watched the results coming through on one of his desk screens, not that he could understand the details, but the overall impression was easy enough.
“There’s still something there,” Tunde said. “Hysradar scan shows it’s smaller than before. We’re probably picking up the outer lattice sphere. Wait—yes, it’s rotating. The shell has gone. And there’s a very strange quantum fluctuation signature inside it. That wasn’t there before.”
“A wormhole?” Wilson asked.
“No. I don’t recognize it at all.”
“Threat assessment?”
Tunde gave him a slightly irked look. “Nothing obvious. I’ll get back to you on that one.”
A picture of Dyson Alpha’s planetary system was building up on one of the bridge portals. The two gas giants were both smaller than Jupiter, orbiting at four and a half AUs and seventeen AUs from their star. The largest of the three solid planets had a diameter of fourteen thousand kilometers and orbited one point two AUs out from the sun. The remaining two were both smaller, and in mildly ecliptic orbits a lot farther out. They called the innermost planet Alpha Major and focused the starship’s main sensor suite on it.
“My God,” Sandy Lanier said. “Will you look at those readings.”
Alpha Major’s visual spectrum showed water on a scale that indicated oceans, and an oxygen-nitrogen atmosphere. It was also a strong source of neutrinos. “A very heavy level of fusion activity,” Russell commented. “I’d say total power generation exceeds our Big15 worlds combined.”
“What the hell uses that much power?” Oscar muttered.
A measurable percentage of it, they discovered, was pumped into communications; throughout the electromagnetic spectrum the planet was shining like a small nova. The starship’s RI began recording the multitude of overlapping signals, but without a key none of its decryption algorithms were of any use.
The greatest fusion usage was the most obvious to see. Space above Alpha Major was thick with activity. Slender brilliant threads of fusion drives created their own ring nebula, extending from the upper atmosphere out to a million kilometers. Fleets of ships were accelerating at three or four gees away from the planet, slashing long scars of plasma across the void before finally cutting their engines to coast to destinations across the star system. Hundreds more were on their approach, firing their engines to decelerate into the perpetual swarm circling the planet.
Over fifty moonlets were in orbit two hundred thousand kilometers out, with knots of small fusion flames wrapped around them as ships came and went. They must have been captured asteroids, their orbit and spacing was too regular to occur naturally. Each one was surrounded by massive industrial stations.
“Don’t they care about their environment?” Antonia asked. “It can’t be safe having fusion ships flying that close to a habitable planet.”
“Those are big ships,” Anna said. “At least the same size as the Second Chance, some are a lot bigger. And their exhaust is helium, they’re probably using boron fusion.”
“Expensive,” Antonia muttered.
“Depends on your technology level,” Oscar said. “This is not a primitive civilization.”
“Where are the ships going?” Wilson asked.
TheSecond Chance began to expand its observation. They found an astonishing level of technological activity on and around every planet. The two outer solid planets, though cold and airless, were dotted by vast force field domes, artificial habitats whose vegetation matched the spectrum to be found on the landmasses of Alpha Major. Fusion globe suns illuminated each one. Spacecraft were almost as numerous as above Alpha Major, wrapping the worlds in a perpetual flexing toroid of blazing light. They also had dozens of industrialized moonlets.
Out among the gas giants, the pattern was repeated. Every large moon was home to the habitat force field domes, and surrounded by ships and industrialized moonlets. The thin rings orbiting the gas giants played host to thousands of stations that latched on to the rocky particles, slowly digesting them. As for the dozens of outermost moons—rocks that were essentially large asteroids—force field habitats had engulfed them completely. Tightly whorled contortions in the magnetosphere revealed colossal structures in low equatorial orbit. When the Second Chance’s sensors tracked them, they found they were trailing cables or pipes down into the upper cloud bands.
As the details appeared on the bridge portal they made Wilson nostalgic for the future he’d thought he was pioneering back in 2050, the never-happened golden era of humanity’s High Frontier. This was the kind of intersystem society any technological civilization would eventually build if it was somehow cut off from the stars.
Why would it be cut off, though?
Three hours after the barrier had vanished, Sandy turned the sensor console over to Anna, though she hung around for a couple of hours to see what developed.
One of the secondary telescopes was watching the turmoil that was space around Alpha Major. “Looks like some ships are heading outsystem,” Anna said. Eleven streaks of fusion plasma were visible beyond the distance when most of the ships had powered down to coast-flight mode. “Accelerating at five gees, and have been for three hours now. That’s one hell of a velocity they’re hitting. I hope they’ve got force field protection. A small molecule can seriously ruin your day at that speed.”
“I’m tracking several similar flights from both gas giants,” Jean Douvoir said.
“Any coming our way?” Wilson asked.
“Not really, sir. Four are on an interception course for the Dark Fortress. One of the others will pass within eight AUs.”
“Safe enough, but keep tracking it. If it alters course in our direction I want to know about it.”
“Aye, sir.”
“Tunde, do you think they’re capable of detecting our hysradar scans?”
“I’d say they have the technology to detect quantum wave fluctuations, which might give them an indirect clue we were here. But we haven’t detected any hysradar emissions from inside the star system, so they probably haven’t got a direct detector. Why would you build a hysradar if you’re confined inside a barrier thirty AUs across?”
“Do they have the technology to build the barrier?” Wilson asked sharply.
Tunde grimaced, reluctant to give an opinion. “I’d say not. Judging from what we’ve seen, I’d put them on a par with us, except that they don’t have wormholes. The Dark Fortress is orders of magnitude above anything we’re capable of.”
“That implies the barrier was put up by an outside agency.”
“It’s looking that way, yes.”
“They were confined inside, then. Someone thought they were a threat.” Wilson turned his attention back to the magnificent astroengineering accomplishments which the sensors were revealing. Given his background, it was hard not to be envious of Dyson Alpha’s civilization. “Why?”