by Ian Douglas
“It’s gone,” St. Clair said. “Something came in here and ripped it apart!”
“That . . . is not . . . possible. . . .”
A piece of spinning debris the size of a house collided with Ad Astra’s engineering section, and things began to get worse.
Much worse. . . .
CHAPTER
TWO
Ad Astra hurtled toward the loom of the supermassive black hole ahead.
“Bridge, Engineering!” Martinez called. “The stardrive is off-line!”
“What happened?” St. Clair demanded.
“Something hit us, sir. Something big.”
“Where?”
“Engineering hull. We’re losing atmosphere down here, fast . . .”
St. Clair glanced up at the titanic black hole just ahead. Already it looked a little larger . . . a little closer . . .
“We’re going to need shift capability in like the next few minutes,” he said. “Get us back on-line, and do it now!”
“Working on it, sir.”
He almost added further . . . encouragement, but it would be useless to keep harping at his people, St. Clair knew. They knew their jobs. He stifled the shrill exhortations that came bubbling up in his mind, and transmitted instead a calm-sounding “Good.”
But the Tellus Ad Astra was hurtling toward the SMBH at pulse-pounding speed. And that was far from good.
“Helm! Can we maneuver clear?”
“Working on it, sir. But . . . I don’t think so. We emerged from shift with a hell of a lot of velocity, and I think we picked up more speed by skimming the Harmony Singularity. We don’t have stardrive, we don’t have maneuvering, and that thing up ahead is not going to let go.”
Which meant that even with its gravitic drive, it would take time and a lot of energy to break free. Energy they had. Time . . .
That was another matter entirely.
“What happened to Harmony?” Symm asked.
“We’ve got . . . fragments,” Lieutenant Anna Denisova reported. She was the ship’s sensor officer, charged with keeping track of what was happening in Ad Astra’s immediate vicinity. “Big fragments.”
St. Clair didn’t need sensors to know that—some were visible within the display above his head. Black, ragged-edged, some pieces the size of mountains, others like pebbles or sand, all in a free-fall tumble toward the central SMBH. The smaller pieces were rattling off the bridge’s outer structure like hail off sheet metal. A cloud of the stuff must be pacing the Ad Astra; if one of those rocks hit with a large difference in relative speed . . .
Hell, maybe that was what had happened. A small pebble, rather than something the size of a house. If it hit at a hundred kps, it would cause quite a lot of damage.
Or . . . maybe Ad Astra had taken damage in a near passage of the small black hole—the Harmony Singularity. The decelerative field the Liaison had mentioned hadn’t worked, obviously—blown away with Harmony’s destruction. Moving with a residual velocity of a hundred kps or so, then skimming the Harmony Singularity . . . yeah, that might explain it.
“It is not possible,” the Liaison said, “that the Harmony Habitat should have been . . . obliterated in this manner. It was far too large.”
“Nothing,” St. Clair replied, “is too big to fail. At a guess, I’d say your Denial friends were here within the past five years with enough firepower to at least weaken the thing’s hull. The stress of orbiting the black hole would do the rest.”
“Why . . . do you say within the past five years?” the Liaison wanted to know.
“Because we parked five light years outside the core a few moments ago, and looked at it through a grav lens. It appeared intact from there . . . but the light we were seeing was five years old.”
“Of . . . course. We should have remembered that. . . .”
“Hey, it takes some getting used to. When were you at Harmony Hab last?”
“Perhaps three of your years.”
“That nails it down further,” St. Clair told the alien. “The only way to pinpoint a date would be to move out from the black hole a few light days at a time, taking a look back and seeing when the habitat breaks up.”
“We must do this,” the liaison said.
“We will . . . if we can get ourselves out of this gravity well,” St. Clair replied. “I suggest that you leave the bridge, and let us work on that.”
“You will keep us informed. . . .”
“Of course. You have bridge link access.”
“We . . . do not understand how this could have happened.” The alien environmental unit spun and silently floated off the bridge.
“He sounds pissed,” Symm said.
“Well . . . his galactic capital has just been blown to hell by parties unknown,” St. Clair said. “Understandable.”
The Ad Astra gave another sharp, brutal shudder, and St. Clair wondered if the ship could hold together. She’s definitely not designed for maneuverability, St. Clair thought. More like a houseboat with a jet engine bolted on the back.
In other words, he knew, strong tidal forces will rip her apart.
The good news was that the central SMBH was so large—the size of Mercury’s orbit—that its gravitational gradient would be fairly gentle. The bad was that the Ad Astra was accelerating so quickly in that gravitational field now that torque and flexing in the structure’s framework might well destroy them before they had a chance to be sucked into the black hole.
And there wasn’t a damned thing that St. Clair, as ship’s captain, could do about it.
Which is when something else occurred to him. “Where’s the Coad monitor?” he asked.
“Eight hundred thousand kilometers ahead,” the third navigator said.
“So far?”
“Shiftscatter, my lord,” Lieutenant Mason, the helmsman, added.
So the Medusan ship had come through . . . but the mathematical vagaries of this gravitationally distorted spacetime had scattered the two when they’d emerged. Maybe they’d been relying on some sort of beacon or trigger to drop them out of shiftspace inside the decelerative field, and overshot because the beacon was gone. Maybe, maybe, maybe . . .
Too many unknowns.
The alien vessel was now farther ahead of the Ad Astra than twice the distance between Earth and Earth’s moon. That was still close compared to the vast sweep of the accretion disk below . . . but all that distance emphasized how tiny even a vessel as large as the Ad Astra truly was, isolated in emptiness.
Faster, now. They were moving much faster, accelerating until the accretion disk, 300 million kilometers across, was visibly drifting past Ad Astra’s keel, like a mass of white clouds above the Earth seen from orbit. The face of that disk was intolerably bright, especially in toward the center, where it glared hot and rich in UV, X-rays, and hard gamma. The AIs controlling the video input were stopping down the brightness to avoid injuring human optics in that storm of light, as brilliant as the face of the sun.
The black hole itself loomed almost directly ahead . . . and it didn’t look as St. Clair had pictured it. It was black, yes . . . or what he could see of it was, an eye-aching blackness so deep his gaze tended to slide right off the thing, with nothing at all upon which to focus. Only half of the sphere was visible above the swirling storm of the accretion disk. The hemisphere he could see was bounded by a shimmering half ring of optical distortion; light from beyond the SMBH, from the star clouds of the Galactic Center and from the opposite side of the accretion disk, was being weirdly bent by the intense gravitational field close to the black hole’s event horizon. The half ring appeared silvery and mottled, and it was moving as the Ad Astra’s perspective shifted.
“Helm . . . we need to break free. Now.”
“Working on it, sir.”
He could feel a deep-down vibration, an ongoing shudder transmitted through the seat of his command chair as the ship marshaled titanic energies from the vacuum and directed them into its gravitic drive. Ad Astra was changin
g course, pulling up against the drag of that black monster ahead, but so slowly.
Too slowly.
The central regions of the accretion disk were hotter, more active, tinged with violet radiance, while the outer regions were cooler and redder. St. Clair could see flashes and pulses of light from the innermost parts—flares of high-energy radiation like planet-devouring bolts of lightning.
“How’s the shielding holding up?” he asked.
“It’s holding,” Subcommander Michael Seibert reported. “Just barely . . . but we’re okay so far.”
Which was no guarantee that the electromagnetic shielding protecting the Ad Astra from the horrific storm of radiation outside would continue keeping them safe. Like the shift drive, the shielding technology had come from the Coadunation . . . and St. Clair wasn’t yet certain that he trusted it. Radiation levels within the core were far, far higher than out in the galactic suburbs, where Sol circled, necessitating EM shields considerably more efficient than those currently used by Earth. St. Clair still wondered, however, if it wouldn’t have been better if the United Earth Directorate had waited until it developed these gimmicks on its own.
“My lord,” Craig Mason said, the stress clear in his mental voice. “We’re not going to make it.”
A computer-generated schematic appeared in a window opening in St. Clair’s head. Mason’s efforts had indeed deflected Ad Astra’s headlong plummet toward the SMBH . . . but not quite enough. They would be entering the black hole’s ergosphere in another five minutes.
“Is there anything else we can try?”
“Damned if I know, sir,” Mason said.
“Newton! What are we missing?”
“There is one possibility,” the voice of the ship’s computer replied. “A slender chance.”
That caught St. Clair’s attention. “What is it?”
“If we jettison one of the cylinders, its fall might eject us from the ergosphere.”
“I looked at that, Lord Commander,” Mason said. “I couldn’t. I couldn’t. . . .”
Newton uploaded another schematic, one showing the jettison option. Ad Astra’s two habitation cylinders, each thirty-two kilometers long and six and half wide, represented by far the majority of the ship’s mass. Drop one at exactly the right moment, and it would fall deeper into the black hole’s gravity well . . . but the drop would kick the other—plus the attached engineering hull—higher, in a stark demonstration of Newton’s third law. There were stars, St. Clair knew, that once had been part of a binary pair that strayed too close to the relentless tug of a black hole. One member of the pair had been devoured; the other had been slingshotted at a substantial fraction of the speed of light into deep space.
And what had worked for a star would work with the double-hulled colony transport.
“Craig,” St. Clair said, “if there’s a chance here in hell . . .”
“Sir . . . I can’t. I can’t! My family is in O’Neill Starboard!”
“It’s okay, son. . . .”
“Sir, if you’re going to eject one of the cylinders, I want to be with them!”
The helm officer’s voice was shrill, sharp-edged with panic. Briefly, St. Clair considered relieving the man, letting him go join his family. According to Mason’s bio, he had a wife, a husband, and three kids living in Goddard, one of the starboard side’s cities.
“The window for that option,” Newton said with implacable calm, “has closed.”
St. Clair checked the numbers flowing back through his link with the ship. It would have taken nearly ten minutes to seal off one of the cylinders and prepare it for jettison . . . and there simply wasn’t enough time left.
And . . . would he have been able to give that order, any more than Mason? Tellus Ad Astra carried a million human passengers and several hundred thousand AI robots. Most lived in the two hab cylinders, distributed roughly half and half. Could he have given the order to drop half a million souls into the maw of the black hole, even to save the others?
St. Clair wasn’t at all certain that he could.
“There is still the possibility,” Newton went on, “of catastrophic jettison.”
Ad Astra gave another hard shudder as if to underline the possibility. If the ship’s structure couldn’t hold up to the stresses of flashing low above the event horizon of a black hole, they might get a cylinder jettison by accident instead of deliberately.
“Monitor the hull stresses,” St. Clair told the computer. “If it looks like we’re going to lose a cylinder, orient the ship to take advantage of it.”
“So that the surviving cylinder and the engineering and drive sections survive,” Newton added. “I will do so if possible. I cannot guarantee—”
“Just do what you can, damn it!”
“Lord Commander . . .” Mason began.
“It’s okay, Craig,” he said. “We’re not going to jettison your family.” Not deliberately, anyway, he added to himself. Not if we can help it.
“Thank you, sir.”
“If there’s any way possible, we’re going to come through this together. All of us.”
But circumstances, he knew, together with the implacable laws of physics, might yet make a liar of him.
Three minutes. The curve of the black hole, edged by its arc of optical distortion, seemed to float within its accretion disk just ahead, though the ship’s course correction was edging them now toward one side.
“Radiation levels are increasing, my lord.”
“I see it.” Cosmic rays, hard X-rays and gamma radiation—the galactic core spawned the stuff in vast and seething clouds. Ad Astra was plunging through an increasingly fierce storm of extremely high energy radiation.
A bright flash strobed against the visual display, and was instantly lost within the glare of the accretion disk.
“The squid ship is gone, my lord!” Denisova reported. She sounded badly shaken. “It just . . . blew. . . .”
What had happened? The aliens possessed technologies—including materials technologies—far ahead of what was possible so far for Earth. If an advanced-tech Medusae ship couldn’t hold up against this battering, what hope might there be—could there be—for the fragile human colony vessel?
“The alien’s path was slightly below ours, sir,” Denisova continued. “Closer to the accretion mass. Maybe . . .” Her voice trailed off.
“They might have hit a piece of the destroyed habitat,” St. Clair said. “Or a planetesimal.”
Accretion disks—vast clouds of matter drawn into an orbiting whirlpool flattened by orbital mechanics and electromagnetic fields—were ideal places for the birth of new worlds, even of stars. Or perhaps the nameless alien vessel simply had dropped into a volume of space too richly populated by ultra-high velocity dust particles and atoms of hydrogen gas.
He’d have to worry about that some other time.
Two minutes . . .
“Engineering,” St. Clair said over the open channel. “Please tell me you’re about to produce a goddamned miracle.”
“Sorry, my lord,” Martinez replied. “We’re fresh out of miracles. The jump drive is wrecked; we’re going to have to grow a new one from scratch. And the gravs are pushing as hard as they can, but it’s simply not enough to break free.”
“Can you achieve orbit?”
A long pause followed the question.
“Maybe,” Martinez said at last. “Big maybe. But we probably won’t survive the environment.”
“Don’t worry about probables. Give us as much time as you can.”
“Yes, my lord.”
The outer edge of a black hole’s ergosphere could be defined as the distance from the singularity at which the hole’s escape velocity was equal to the speed of light. Hit that, and the Ad Astra would never pull away . . . not unless Engineering was able to repair or replace the stardrive. The zone was also called the apparent event horizon; nothing that happened within it could ever be observed by someone outside.
In fact . . .
“My Lord!” Lieutenant Denisova shouted in his mind. “My Lord, the Medusae ship wasn’t destroyed! It’s still there—I think.”
“What do you mean, ‘I think’?”
“The flash was an energy trail, a kind of wake through the hydrogen gas. But I’m getting the ship’s image up ahead, on the event horizon!”
A window opened in the display, showing a highly magnified view of what appeared to be the Medusan ship—grainy, pixelated to the point of incoherence, and apparently frozen in place deep within the field of intense gravitational distortion around Sagittarius A*.
But it wasn’t orbiting the black hole. It appeared to be frozen against it, frozen in time.
ONE OF the curious bits of physics associated with black holes is the fact that as a ship falls deeper and ever deeper into a gravity well, the increasing gravity acts in exactly the same way as relativistic time dilation. Time itself slows as the doomed ship approaches c; at the same time, the image of the ship, carried by relativistically distorted light waves, appears to slow . . . slow . . . and finally stops, freezing at the apparent event horizon.
So the Medusae on board the Coad vessel might already be dead, stretched by tidal forces in a way described by the unpleasantly evocative and vivid term “spaghettification,” but the moment of their entry into the SMBH’s ergosphere was frozen for eternity on the apparent event horizon.
“An Einstein ghost,” Symm said.
“Maybe,” St. Clair agreed. “I wonder if they broke free? Or maybe they’re still falling?”
There was no way of telling.
In any case, St. Clair had his own set of worries at the moment, and unless the Coad ship offered clues for Ad Astra’s escape, he had no time to waste on them.
One minute. . . .
The shuddering grew to a crescendo of vibration, rattling the ship and St. Clair’s seat and the very fiber of his muscles and bones. Somewhere, a radiation alert was sounding, and the glare of light both on the projected holographic display around him and within the open displays inside his own head was fading rapidly, dwindling to a sullen red glow before fading even more, then, into black. The bridge was still visible—he wasn’t going blind, which had been his first sharp, panicky thought—but the light from outside the ship was stretching out into the red end of the spectrum . . . and then beyond, into infrared . . . microwave . . . radio. . . .