Andromedan Dark

by Ian Douglas

  He was going to release Lisa . . . emancipate her. Someday. A growing number of AIs nowadays were emancipated, though quite a few voices—including, surprisingly, those of some robots—felt that a free choice for robots wasn’t the answer. After all, if a mind didn’t know it was enslaved, if it was happy doing what it was doing, releasing it might actually be cruel.

  St. Clair knew he was going to need to talk this over with Lisa soon, maybe once she’d had a chance for the new settings to settle in. He wasn’t sure how he felt about that himself. Ever since Natalya had told him they were through, he’d been so desperately lonely.

  Lisa had been his salvation.

  It was one thing to be distracted by such thoughts on the way, but now that he had arrived, all his training and experience kicked in, and he focused on the task at hand. He swam onto the bridge, entering the huge, empty cavern, brightly lit at the moment by the multitude of brilliant stars gleaming around its perimeter. “The Lord Commander is on the bridge,” Symm said out loud. And then: “You have the bridge, my lord.”

  “Thank you, Excomm.” He settled into his seat, which shaped itself to hold him down, to keep him from drifting around. Background chatter, the communications among various shipboard departments and stations, whispered in his ears, giving range, mass, power levels, the minutiae of navigation. Projected in the air directly ahead of him against the thick stellar backdrop was the other ship . . . though it didn’t look much like one.

  “What the hell is that?”

  “We assume it’s an alien starship, my lord,” Symm told him. “I told you it was big.”

  “It looks more like a moon. Diameter . . .”—he checked the specs he was receiving—“a bit more than four hundred kilometers. Mass . . . nine times ten to the nineteen kilograms. Volume . . . thirty-two point five million cubic kilometers.”

  Good god.

  “It dropped out of stardrive fifteen minutes ago, and has been pacing us since. Range . . . two hundred eighty million kilometers.”

  “Velocity?”

  “Same as ours, my lord. Point seven one cee.”

  At seven-tenths of the speed of light, Ad Astra was only just beginning to enter the realm of large-scale relativistic effects, with the stars ahead taking on a bluer tint, the stars astern becoming slightly redder. That velocity was a compromise. St. Clair wanted to put some distance between the ship and the SMBH astern, but he didn’t want to start messing with time dilation. If the unknown aliens who’d attacked them hours before returned, he wanted the Ad Astra, as much as possible, to have lost herself in the enormous emptiness surrounding the central black hole. Travel too fast, however, and time would slow for Ad Astra and those aboard her. Years might pass in the Galaxy outside, while hours or days passed for ship and passengers. St. Clair wanted Ad Astra to return to the same Earth that she’d left.

  He took a closer look at the alien vessel trailing the Ad Astra. It looked familiar, somehow. He pulled down some additional data, then nodded. “Mimas,” he said.

  “I beg your pardon, my lord?”

  “That thing following us is almost exactly the same size as Mimas . . . one of Saturn’s inner moons. The density is a lot higher, though. . . .”

  “Probably because Mimas is mostly water ice,” Symm told him.

  “And Mimas rarely zips off for joy rides around the Galaxy,” St. Clair added. “Looks like someone just found a convenient moon, fitted it out with a propulsion system and life support, and took off.”

  Despite his seeming nonchalance, St. Clair was both impressed and disturbed by that fact. He stared intently at the object. The surface of the spherical body was heavily crater-pocked. One large crater even suggested the enormous gash of Herschel Crater, on Mimas. The smaller craters tended to be bright-walled and prominent . . . a hint that the outer shell of that thing might be water ice.

  “It would be interesting to know if they’d installed weapons systems in that thing as well,” Subcommander Webb said.

  “We’ll assume they did.” He glanced around the bridge, and saw the Medusan liaison nearby, hovering in its silvery, frost-coated pod. “Liaison?”

  “We are here, Humans.”

  “How about it? Does anybody you folks know tool around the Galaxy inside a mobile moon?”

  “A number of technical civilizations use found artifacts as spacecraft hulls—generally asteroids. Many hollow such bodies out and use them as the outer shells for self-contained orbital space colonies, but a few have given them mobility. We have never seen such an adaptation this large before, however.”

  “The big question is whether these guys are related to those three robot ships that went after us earlier.” When there was no immediate answer, he added, “Think they might be?”

  “We do not know, Humans.”

  “They’re just hanging off our ass out there,” St. Clair said. “Comm . . . any incoming from that thing? Radio? Laser? Signal flags? Anything?”

  “No, my lord.”

  So maybe the unknowns communicated using phased neutrino beams, modulated gravity waves, or something even more exotic. If they wanted to talk, though, he felt sure they would find some way to make their intentions known, just as the Medusaens had years ago.

  “Helm. Boost our speed to near-cee.”

  “Increase speed to near-cee, aye, aye, my lord.”

  And Ad Astra began accelerating.

  “My Lord,” Denisova said. “The alien is matching our pace.”

  “Very well. CAS! Bring a squadron up to ready status and stand by.”

  “Aye, aye, my lord.”

  Although the alien hadn’t made any hostile moves yet, St. Clair didn’t trust them and he wasn’t going to give them the chance. The fact that two sets of alien vessels had found Ad Astra in the middle of all of this emptiness was suspicious. Those first three—those robot attack ships—might have been staking out Sagittarius A* after the destruction of the Ring, but the appearance of another ship suggested that they were related to that first group somehow. To assume otherwise ignored just how slim the chances of two random encounters in the middle of so much emptiness actually were. This moon-sized ship might be an enemy of the robots deployed in local space to find them, but St. Clair wasn’t about to take the chance.

  “Alien is closing, my lord. Slowly. They won’t intercept us at this rate for hours.”

  “Keep an eye on them.”

  Okay . . . the aliens were closing, but at a snail’s pace. Was that in itself an attempt to communicate? Or was someone trying to sneak up on the Ad Astra in a 400-kilometer mobile moon?

  God, the power that thing must be using, though! As Ad Astra reached ninety-nine percent of the speed of light, the alien comfortably matched that velocity . . . and a wee bit more. Apparently it was using a gravitic drive quite similar to the one on Ad Astra, bending space ahead of the vessel to create a depression in the spacetime matrix, a depression into which the ship continually fell. The system allowed tremendous accelerations—tens of thousands of gravities—without smearing the passengers and crew into a thin red jam across the ship’s aft bulkheads.

  At 50,000 Gs they could from a standing start nudge up close to the speed of light in ten minutes. They still couldn’t pass that magical speed; for that they needed to have a functional stardrive. But gravitational acceleration affected every atom in the ship uniformly, so there was no crushing G-force with which to contend.

  “Radiation levels are increasing, my lord,” Denisova reported.

  “To be expected. It’s gassy in here.” At near-c velocities, free-floating atoms of hydrogen became high-energy particles, deadly to unprotected tissue—cosmic rays. “Mr. Seibert. We handling it okay so far?”

  “Yes, my lord,” Seibert replied. “Positive deflector fields are up, and the water shielding is handling anything that makes it through that.”

  St. Clair considered the tactical situation closely. They couldn’t run—the stardrive was still hours away from being repaired. They couldn�
�t hide—there were vast and opaque molecular clouds ahead, but the nearest was a good twelve light-hours away. Same for nearby stars; the nearest was two light-days distant. The SMBH was astern . . . but, again, light-hours distant, and St. Clair wasn’t eager to get close to that thing again.

  And they couldn’t fight. The pursuing vessel could swat the Ad Astra like a fly, if its size and power consumption were any indication of its military capabilities.

  Which left . . . what? Communication? Surrender?

  Communication wouldn’t work if they didn’t know how to talk to the aliens, and that in turn eliminated surrender because that act required some sort of exchange understandable by both parties. Besides, St. Clair wasn’t ready yet to surrender the lives of a million souls into the hands—or whatever—of unknown sentient beings with unknown motives, drives, and attitudes. There were damned few options open to him.

  Maybe, though . . .

  “Excomm . . . ready the ship for drive separation.”

  He saw her surprised look as she glanced back over her shoulder at him. “Sir?”

  “Do it.”

  “Aye, aye, my lord.”

  “Helm . . . we’re going to want to come to a rapid stop relative to local space just before we separate. Program it.”

  “Aye, aye, sir.”

  And the next few minutes dragged by with agonizing slowness.

  “Lord Commander,” Excomm Symm finally said, “we are ready in all respects for separation. Helm will initiate deceleration on your command. Connector sections have been evacuated and sealed.”

  St. Clair took a last look at the available data. The view outside the ship was weirdly distorted by their speed, an entire universe compressed into a tight, glowing ring circling the ship at thirty degrees from dead ahead. The trailing alien was lost in the distortion, but Ad Astra’s sensors indicated that the moon-sized vessel was still there, closing at a few thousand kilometers per second, and still a couple of hundred thousand kilometers astern.

  “Helm . . . decelerate the ship.”

  “Decelerating . . . aye, aye, my lord.”

  There was no shock or strain, no sense of changing motion, but the view outside began to smear back across the encircling sky as the surrounding stars slowly resumed their true positions.

  “Point eight-five cee,” Lieutenant Mason reported. “Point eight . . . point seven-five . . .”

  Slowly, the stars continued to crawl across the heavens, until they filled the entire sky once more.

  “Point six cee . . .”

  Still decelerating. “What’s the alien doing?”

  “My Lord,” Desinova said, “he appears to be decelerating as well . . . matching our velocity perfectly.”

  Good. If that mobile moon was out to destroy the Ad Astra, it wouldn’t just play games with them. Either those aboard wanted to communicate with the UE vessel, or they were simply observing it. Maybe they just wanted to escort the Ad Astra out of the area.

  They would find out in a few more minutes.

  “Velocity now at point five cee.”

  Half the speed of light. The relativistic optical effects were gone, now, but they were still moving too quickly for separation. St. Clair’s chief concern was the safety of the hab cylinders. Specifically, if the drive module released the cylinders and went off to confront the alien, the cylinders would continue hurtling off at 150,000 kilometers each second, with no way to slow down. If anything happened to the drive unit—if it got fly-swatted by that moon, for instance—the O’Neil colony would continue drifting at high speed until it slammed into something—a cloud of molecular hydrogen, for instance, or a cloud of dust particles or something else that the meteor defense grazers couldn’t handle.

  When that happened, Tellus’s velocity would be transformed into radiant heat, and the O’Neill cylinders would briefly flare into incandescence before being reduced to a fast-moving cloud of hot plasma.

  It took ten minutes to decelerate from near-c. When St. Clair gave the order to separate, they were moving at less than five kilometers per second. If the colony encountered a dust cloud or asteroid belt at that speed, its computer-controlled grazer defenses would be more than adequate to burn a safe path through the vacuum.

  The improbable odds of them hitting something larger continued to hold.

  With a jolt, the CCE section separated itself from the twin cylinders. It left behind a small secondary engineering section that would continue to feed power to the cylinders for life support and to maintain their rotation, but the colony was now without any type of drive.

  By long tradition, the part of the ship containing drive, engineering, and command bridge retained the name—Ad Astra—even though it was only a couple of kilometers long. The much larger O’Neill cylinders left behind would formally retain the name Tellus, since it was a repository for Earth-human technology and culture. A small point . . . but an important one for a species more concerned with personal identity than, say, the Medusae.

  “CCE separation complete,” Symm reported. “Ad Astra is now maneuvering free.”

  A graphic image hovering in front of St. Clair’s face gave him the same message. The command and drive unit was clear now of the colony’s stern endcaps, drifting back smoothly. “We are clear of Tellus and ready to boost.”

  “Bring us about, Mr. Mason.” The Ad Astra, as if delighted to be free of the burden of the two colony cylinders, pivoted now to face the alien.

  A last check of all systems . . . they were good to go.

  “Let’s go have a look at these people,” St. Clair said. “Helm, take us ahead. Accelerate to fifty Gs.”

  A communications chime sounded within St. Clair’s brain. It was Adler, calling from his office in the port cylinder, now dwindling rapidly into invisibility astern.

  “Make it fast, Lord Director. We’re kind of busy right now.”

  “The computer just told me you’ve separated from the colony! What the hell do you think you’re doing?”

  “I’m going to go have a little chat with the aliens. Mind the fort until I get back, okay?”

  “St. Clair! What if you don’t come back?”

  “Then we’ve successfully completed Ad Astra’s mission, by placing a functioning O’Neill colony at the galactic core. The expedition is all yours, Lord Director. Good luck. . . .”

  “Damn you, St. Clair!”

  “Can’t talk now, sir. Don’t worry. We’ll get back to you just as soon as we can.” He cut the channel.

  The alien moon, pocked and cratered, swiftly grew to fill the sky ahead.

  “Tactical!” St. Clair called. “Do we have any solid targets on the surface?”

  “Negative, sir,” Cameron said. “We’re marking some mascons that might be large structures beneath the surface, but we’re not seeing weapons emplacements, drive sections—nothing.”

  Mass concentrations beneath the surface weren’t enough to go on. “What’s our range?” Damn it, with that thing, he thought, he should be asking about their altitude.

  “Twelve hundred kilometers, my lord.”

  “Helm . . . close the range, but slowly. Engineering . . . see if you can project the drive field forward. I want to poke this guy in the face.”

  A nudge from their drive field wouldn’t harm the massive object out there, but they should feel the nudge.

  Like knocking on their front door.

  “Sir!” Denisova called. “They’ve launched a missile!”

  “Anti-meteor defenses to full!” He hesitated. “Wait . . . just one?”

  “Only one, my lord. Length . . . two point one meters. Mass . . . one hundred five point seven kilograms. Velocity . . . eight meters per second.”

  “Eight meters a second,” St. Clair said. “And pretty small. That’s not much of a missile.”

  “Anti-meteor defenses ready to engage, my lord.”

  “Hold your fire.”

  And then, the small moon vanished. One moment it was there, filling the sky ahe
ad. And in the next instant . . .

  “Okay . . . what the hell happened?”

  “The alien appears to have engaged its version of stardrive, lord,” Symm told him. “It is no longer within detectable range.”

  “Keep your sensors sharp, Lieutenant Denisova,” St. Clair ordered. “It may just take a moment for us to see him.”

  If the alien vessel had simply jumped back a given distance, but was still in the area, it would take light time to reach the Ad Astra. A jump of 150 million kilometers, for instance—a distance of one astronomical unit—would mean a time lag of over eight minutes before it reappeared on Ad Astra’s screens. It would take that long for light to crawl all the way back to the ship.

  “What’s the missile doing?”

  “Approaching,” Denisova reported. “But slow. Dead slow.”

  “So . . . a messenger?” St. Clair wondered aloud. “Or a Trojan horse?”

  “Or a probe of some sort,” Symm suggested. “Something to check us out, find out about us.”

  “If I had to guess,” St. Clair said, “I’d have to say that they were offering us the chance to communicate. CAS.”

  “Yes, my lord.”

  “Ready an RS-59 for launch.”

  “Very good, my lord.”

  “Computer! Do we have any xenolinguistics people on the drive unit?”

  “Several dozen, Lord Commander,” the ship’s computer replied. “There are also a number of AI modules with xenolinguistic programming on-line.”

  “Call them,” St. Clair said. “We’re about to put them all to work.”

  The RS-59 was a robot-operated worker drone, one with a generous cargo capacity and the ability to work both in space and in a planetary atmosphere. Launched from the command-control-engineering section’s flight deck, the six-hundred-meter craft would be able to pick up the alien missile and return it to Ad Astra.

  But should I give that order? Damn it, the galactic core had been less than friendly so far, with the Coadunation Ring smashed to pieces by agencies unknown, and then the encounter with the three red-and-black needle-ships. Because of all that, St. Clair was unwilling to trust anybody new right now. If that object adrift out there explodes as soon as it’s brought aboard, or if it houses the equivalent of a hostile electronic virus or other program designed to cripple or destroy the Ad Astra . . .