Galactic Corps

by Ian Douglas

  “Amen to that. The question is, how much of that stuff is natural, and how much artificial? It looks to me like we may be seeing some evidence of engineering, but if so it’s on a galactic scale. If that thing in the spiral is some kind of huge Xul base or fortress, how the hell can we hope to fight something that damned big?”

  Alexander gave a wan grin, though Taggart couldn’t see it in the sim. “We’re not supposed to fight them, remember? Peace. That’s the watchword now.”

  “Peace . . . with something so big and so advanced we’re like insects by comparison? You know, Martin, I really don’t like this.”

  “Me, either,” Alexander replied. “But we’re in the chain of command. Since when did whether or not we liked something have anything to do with what we did?”

  “Yeah. Let’s have a full three-sixty, okay?”

  “Right.”

  The image data stream included information to reconstruct the view in all directions. With a thought, Alexander rotated their shared point of view, allowing the vista ahead to swing to the right. The Spymaster’s vantage point, apparently, was in close to the center of the vast, empty hollow within the starclouds of the Hub. The wall of close-packed reddish suns extended in all directions, more or less equally blurred everywhere by the gas filling the central void. Behind the Spymaster probe, a stargate orbited in slow majesty, a golden hoop twenty kilometers across, the doorway leading into the Galactic Core from Cluster Space. Nearby, like tiny, metallic toys suspended in space, several structures hung near the Gate—the flattened sphere of a Xul fortress, and several tinier objects that were probably Type I or Type II hunterships.

  Alexander never thought he would use the word tiny when thinking of typical Xul structures.

  He studied that Xul outpost. Strange. Alexander had been expecting a much larger Xul presence here. The data gleaned from a Xul ship in Cluster Space had seemed pretty specific, indicating some sort of major complex here, something bigger than anything Humankind had yet encountered. One fort and a few ships might serve as pickets for the stargate, but not much else.

  Taggart and others, though, believed the real Xul presence here lay much closer to the center.

  There was an uncomfortable possibility, though, and that was that some of what they were seeing at GalCenter was artificial, structures built by the Xul.

  A chilling possibility. The ancient enemy of Humankind tended to build on a truly massive scale. But here, within the Galactic Core, against that staggering vista, even the largest Xul complexes appeared reduced to near insignificance.

  If, however, Taggart was right, if the enigmatic structures near the Galactic Center were in fact Xul artifacts, then the Xul were capable of building on a titanic scale that Humankind had never before even imagined was possible.

  They would need to study the Spymaster data closely if they were to have a chance in hell of understanding just what it was they were up against here.

  He found himself dreading the experience, dreading what they would actually find.

  0414.1102 Combat Ops Center,

  UCS Hermes

  1545 hrs, GMT

  Charel Ramsey entered the COC with Lieutenants Cosgriff and Shea. Their boss, the head of 1MIEF N-2, was waiting for them, already in a couch but not yet linked into the system. He was Navy captain Felix Pollard, a rough-edged son-of- a-bitch who’d been in the Navy for almost three decades now, but who’d passed on a number of promotions to flag rank because his love was intelligence work. Informal, even rude to the point of eccentricity in a service that tended to emphasize uniforms, decorum, and appearance, Pollard was perhaps the one man in the entire Commonwealth who best knew the Xul and their capabilities.

  “Gentlemen,” he said with gruff acknowledgment to Ramsey and Shea, then added, “and Lieutenant Cosgriff. About damned time.”

  “We came down as soon as they passed the word for us, sir,” Shea said.

  Pollard grunted. “Strap in. You three need to see this.” The three junior intelligence officers took link couches

  side by side, settling back in their embrace as connector grips grew from the couch frameworks to embrace hands, arms, and heads. Ramsey felt the familiar tingle at the back of his skull, then the flare of light and sensation as data began flooding through.

  The COC briefing center was wiped away, and he was immersed within the spectacular, mind- bending vastness of the Galactic Core . . .

  “We’re still analyzing the data,” Pollard told them, his voice a growl in their minds. “Enough came back to keep an army of analysts busy for the next few centuries. But we have to move on this, fast. General Alexander wants to begin fleet ops in here within the week. And we’re going to need you three to bring us back some specifics first.”

  All three of them had seen “rushes,” the unedited and unannotated images sent back by the first Spymaster to return to Cluster Space. What they were looking at now was far cleaner, more detailed, and more highly interactive. A thought would call up blocks of data describing a partic ular object—or at least best-guess theories about what it might be—as well as hard data such as distances, size, and mass. The four officers—three Navy and Ramsey, the lone Marine in the group—could move through the simulated volume of space quite freely with a simulated velocity many times that of light, observing and examining everything. It was much like immersing within one of the interactive planetariums he’d seen and enjoyed as a kid.

  Their briefing tour began, however, not at the Galactic Core, but from a vantage point high above the Galactic spiral, looking down on the Hub from some tens of thousands of light years out. Every Marine who’d been out to Cluster Space had seen this view with his own eyes, and not just in downloaded sim, and the basic structure of the Galaxy was comfortably familiar—a flattened, central mass of dense-packed suns perhaps ten thousand light years across and six thousand thick. From here, the central bar of the nucleus was clearly visible. Like many others scattered across the cosmos, the Galaxy of Humankind was a barred spiral, with a central core about twice as long, nearly 20,000 light years, as it was wide, imbedded in a glowing, flattened-sphere, beehive swarm of red-hued stars.

  Out from the Hub, past banked cliffs of fast-moving dust and light-obscuring molecular clouds, the galaxy’s spiral arms stretched out into the intergalactic Gulf, two major arms—the Sagittarius Arm and the Norma-Scutum Arm— coming off the ends of the hub bar, and three lesser arcs and arms—the Scutum-Crux Arm, the Perseus Arm, the Local or Orion Arm—in between. Those arms were strikingly distinct against the velvet black of the background space. The appearance, Ramsey reminded himself, was an illusion. The number and density of stars within the spiral arms was actually only about ten percent higher than in the apparently empty voids between. The effect was due to the density pattern moving out through the interstellar medium from the central Core, triggering star formation delineating standing waves. The arms, where interstellar material was being bunched up into stellar nurseries by those waves, were rich with young, hot, and therefore highly visible stars, and the brighter stars in turn illuminated vast fields of interstellar nebulae, which together gave the appearance of distinct spiral arms.

  But the illusion was powerful and compelling. It was startling to see just how dramatically thin the overall galactic disk actually was. The entire disk of stars stretched nearly 100,000 light years from one side to the other, yet the main portions of the spiral arms were never more than about two thousand light years thick, even in toward the Core.

  “We’ve had a general idea of the topology of GalCenter for a long time,” Pollard said. A point of green light winked on within the Orion Arm, between the Sagittarius and Perseus Arms, marking the solar system of Earth. “From Earth-Sol Space, of course, the Core region is blocked by the intervening clouds of dust, gas, and stars. Astronomers estimate that for every one hundred billion photons coming toward us from the Galactic Core, one actually reaches us. We’ve been hampered in our studies of just what’s in there by the barrier
presented by thousands of light years of obscuring dust and gas.”

  As Pollard spoke, the angle of view changed, so that it seemed as though the quartet of viewpoints were zooming in on the spiral arm toward the microscopic point of light representing the Sol system, then flashing in toward the star clouds of Sagittarius, piercing vast, high-banked clouds of light, of myriad shining stars, of streams and blobs and masses of obscuring dust hundreds of light years long on the way in toward the Hub.

  “Back in the 20th Century,” Pollard continued, “we couldn’t see the Galactic Center optically, but we were able to kind of peer through all the crap and into the core region using radio telescopes and devices sensitive to infrared and X-ray wavelengths. Even from twenty- six thousand light years out from the center, out in the galactic suburbs, we could manage a resolution of objects as small as twenty astronomical units across—say, the size of Saturn’s orbit.

  “Since then, we’ve been able to get a better look at things in there from new vantage points, like Cluster Space. But until now, we’ve never actually seen the central region at optical wavelengths.”

  Their viewpoints emerged from a vast, curving wall of stars. “The innermost core of the Galactic Hub,” Pollard went on, “is hollow. The gulf in here is about fifteen hundred light years across. Turns out it’s filled with gas.”

  “Are you saying there’s an atmosphere in here, sir?” Ramsey asked.

  “It’s still a pretty hard vacuum by Earth standards, Lieutenant, but the gas is denser at the Core, more concentrated, than in any other region of the Galaxy we’ve been able to measure. They estimate there’s enough hydrogen here to form a hundred million new stars. Look there. . . .”

  Ahead, a vast ring of nebula stretched across the center of the inner gulf, a thousand light years across and tilted some twenty degrees to the galactic plane, broken and lumpy in places, but giving the impression of great velocity even though it was visually frozen by its sheer scale. Data readouts showed Ramsey that the ring was expanding at 150 kilometers per second. The cloud was cold, at about ten degrees Kelvin; Ramsey’s readouts began describing the cloud’s composition—simple carbon monoxide and hydroxyl molecules, as well as more complex compounds, formaldehyde and formamide, acetaldehyde and ethanol . . .

  “That ring, the astrophysicists say, must have been generated by an incredible explosion in the Galactic Core about one million years ago,” Pollard explained. “It’s a witches’ brew of organic molecules.”

  “Ethanol, I see,” Ramsey put in. “At least the fleet will have a great liberty when it arrives.”

  “Well, the Galaxy is a barred spiral,” Lieutenant Shea added. “I think we just found the bar.”

  “Quiet, you two,” Pollard growled. Their viewpoints continued to descend into the Galaxy’s heart, flashing past the rapidly expanding smoke ring of nebulae. GalCenter was now five hundred light years ahead.

  At four hundred light years from the center they passed an even thicker mass of molecular clouds, a vast and far-flung doughnut shape, dark on the outside, brilliant with shining nebulae and handfuls of bright, new-born stars within. Masers—lasers at microwave wavelengths—howled birth pangs into the cosmos.

  “That expanding ring,” Pollard told them, “which is passing outward through the hydrogen gas in here, is triggering massive star formation. The radio noise was part of the original radio source discovered at the Galactic Center back in the earliest days of radio telescopy. It’s called Sagittarius B2.”

  Closer to GalCenter, now. Though still relatively empty, the gulf was occupied by numerous infrared sources and objects that defied description. Off to one side, 340 light years from the center, was the Great Annihilator, a fiercely white-burning accretion disk spewing antimatter searchlights into the void. A hundred light years above the center, the Arc reached up like a solar prominence, a streamer of gas smeared into parallel arcs by unimaginably powerful magnetic fields and magnetic flux tubes. The ungraspable scale of what he was seeing continued to surprise Ramsey. Each of those lines, according to his readouts, was half a light year wide.

  Farther in still. Gas clouds concentrated and twisted, with velocities ten times higher than would have been expected from gravity alone. Stars swarmed in hot, young clusters.

  Within the embrace of the Arc, the gas was denser still, dense enough that even the tidal forces here could not disrupt it, but there was no evidence of new star formation. Possibly the storm of energies here was so great that stars couldn’t form. Or perhaps something else was in control. . . .

  Twenty light years from the Center, the gas organized itself into a massive accretion disk, circling an innermost void. The young stars were thicker here, clumped in blue-white swarms. A soft glow of X-rays and cosmic rays filled radiant space.

  The mechanism at the center was a complex one, its pieces identified centuries ago by radio telescopes but never well understood. The radio source at the Galaxy’s precise center was called Sagittarius A. Sag A East was off to one side, a bubble of hot gas marking a supernova that must have exploded thousands of years ago. Sag A West was that spiralshaped, twenty-light year cloud of warm but non-ionized gas at the center, while Sagittarius A* marked the exact center. Close by—just one light year out from GalCenter, a supergiant star, ruby-hued and streaming a comet’s tail into emptiness—cast a bloody hue over surrounding streamers and curtains of gas. The tail was stretched out and away, not from Sag A*, but from a nearby cluster of intense, blue-white stars newly emerged from a tattered nebula. That nebula was extremely close to the exact center of the system—a tenth of a light year, perhaps, and the gas and dust comprising it were twisted into bizarre swirls and fragments that gave mute testimony to the violence of what was going on in there.

  Ramsey tried to understand what he was seeing. The program he was using supplied labels for the various objects at his request, as well as data like mass and velocity. The cluster of intensely blue stars near the center was IRS-16—for “Infra- Red Source.” Gas speeds within the cluster approached 1,000 kilometers per second. The red star was IRS-7.

  Closer in still, a tortured red star labeled S-2 appeared to be hanging at the very edge of the central object.

  “S-2,” Pollard told them, “has been known for a long time. Its orbit was first tracked from Earth seven or eight hundred years ago, and it provided the first hard data proving that there was a supermassive black hole at the Galaxy’s center.” Which made sense, Ramsey thought. That was the beauty of Kepler’s laws of motion. Know an object’s orbit and its velocity along that orbit, and you knew the mass of what it was orbiting. “S-2’s orbit is highly eccentric,” Pollard went on. “But at perigalacton, at its closest approach to the center, it’s only seventeen light hours out, and traveling at better than 5,000 kilometers per second.

  “The math works out to something like two million solar masses in the surrounding stars, gas, and accretion disk, and another two million to three million suns inside that thing at the center. It has to be a black hole . . . given that much mass in such a tiny volume of space.”

  “So what’s the problem, then?” Ramsey asked. “We’ve known about black holes for centuries.”

  “Right,” Cosgriff added. She’d studied to be a theoretical cosmologist, Ramsey knew, until she’d decided to join the Corps. “Once a star just a few times more massive than Sol goes into gravitational collapse, nothing can stop it from falling into a singularity . . . a black hole. Two million solar masses? Yeah, that would make a nice, fat one.”

  “The problem,” Pollard told them, “is that whatever we’re seeing there at the exact center, it isn’t a black hole. We ought to be seeing something like a much larger version of the Great Annihilator, which is over there. What we’re seeing instead . . . well, here, look . . .”

  Pollard zoomed the simulation in even closer, and Ramsey peered hard into the veils of tortured gas and dust. Unfortunately, the program linking him into the simulation appeared to have reached the limit of its re
solution. He would have expected to see something at the center matching his expectations of a typical, if very massive, black hole— a spot of emptiness, perhaps, at the center of that swirling, three-armed spiral of gas just outside.

  What he saw, what little he could make out, was quite . . . different. Its shape overall appeared vaguely spherical, but details eluded him in strangeness and in the shroud of mist. Eventually, though, he could make out shadows and interpenetrating geometric shapes which gave it a decidedly artifi c i a l feel . . . and yet the thing must be enormous, some millions of kilometers across.

  “What the hell are we looking at?” Ramsey asked.

  “We’re not entirely sure, Lieutenant,” Pollard replied. “We know from S-2’s orbit that there’re about two million solar masses packed into that tiny, central volume, and, as Cosgriff pointed out, that means it must be a galactic black hole. But if so, then the reason we’re not seeing something like the Great Annihilator is that this black hole is shrouded or surrounded by something, as though it’s walled up inside an artificial shell.

  “We think—and this is quite tentative at this point—but we think that what we’re looking at is a kind of Dyson sphere. Nothing else we’ve been able to come up with would explain the facts.

  “And if we’re right, it means that the Xul may be a lot further along technologically than we ever dreamed, and that means that we, all of Humankind, may be in very serious trouble indeed. . . .”