UV Ceti's pale red-orange light bathed their skins, and the observation room,
with the same eerie glow that must have greeted Arnold Hasselberg seventy-eight
years earlier. They were still slowing into an orbit after having been
revived, the engines producing a comfortable 0.8 g of deceleration. On
one communications console, the repeated bleeps from a radiobeacon, placed in
the system decades ago by investigators, warned all who listened to the dire
threat from drifting chunks of a former planet — and of a tiny hole in
space.
And that was when the typing urge struck Torra Zorra again, a hundred times harder than it had in Human-Centauri space.
It wheeled at a lightning pace to the closest keyboard, not having to say a word. Ken and Jennifer ran after it as hard as they could. The digits of three of its four hands flew across the keys in a blur, clacking out the sentences: "Arnold here. Thank goodness you've all arrived! It's so much easier to talk to you when you're up close."
"Um, hi," Ken answered, not sure which direction he should be speaking.
"Can you hear us?" Jennifer asked.
Torra typed: "Barely. But I can see you just fine. I can see anything I want to, anywhere, actually."
"Anything anywhere?" Torra enunciated carefully.
"Anything anywhere," the presence typed through Torra. "When I drifted into the unlinked hyper hole in the planet's remains, I entered parallel space and never came back out again. As far as real space is concerned, I'm travelling at infinite speed. So,"
Ken mumbled the answer as Torra typed it, "You cross every point in real space simultaneously."
"So you're alive?" Jennifer asked. "In parallel space? For seventy-eight years with no food or oxygen?"
"Sorry, could you speak up?" the Centaurian channeled.
Jennifer sighed brusquely and pulled up a keyboard of her own. "You're still alive in parallel space?" she typed, her words flashing on another screen.
"Well . . . . . . . . . yes and no. I don't think I still have a body. Matter has no more meaning in parallel space than time does."
Ken leaned over Jennifer's keyboard and typed, "How do you see and think without eyes and a brain?"
Torra paused, receiving nothing. Then: "I don't know."
"I've got a question," Torra said, informing his companions that the next thing he typed would be his own thoughts. He typed, "Our history says that you disappeared just a few hours after the first hyper bomb detonated. This was years before parallel space and hyper holes were even named. How do you know what they're called?"
Torra's hands flew into action of their own accord once more. "I told you I exist everywhere. In deep space, in the interiors of stars and planets, inside other people's bodies . . . and in regular offices and libraries. Any place a display screen gives off light or light reflects off a piece of paper I can read it. I tried to read every paper on phased antimatter bombs and the holes they punch in space as soon as it was published, and a few of them even before that. I've become quite the self-taught expert in the field of parallel space physics, if I do say so myself."
"And me?" the Centaurian enunciated, not wanting to type this personal question. "How do you control me?"
"I don't know that either," his hands typed. "I've being putting myself inside other people's heads for decades, hoping some of my thoughts would get "picked up". I had some barely-noticeable success in the early years when some investigators came to study the UV Ceti IV hyper hole, but it only lasted when they were nearby. However it works, it seems to come out of the hyper hole I entered. It took me decades to be able to stretch any kind of mental influence as far as another star system. With you I finally got lucky. And just in time, it would seem."
"Just in time?" Jennifer typed, visibly nervous. "Just in time for what, precisely? You said everything was going to end soon. *Everything*?"
"The supermassive black hole at the center of the Milky Way," Torra typed. "Sagittarius A. It's nearly three million solar masses right now. It's close to the upper mass limit for a black hole."
"What?!" Ken barked. "That's crazy! There is no upper limit to the mass of a black hole! The whole universe is just the interior of a great big black hole, with zillions of solar masses!"
"There's no upper limit in *real space*," the Centaurian's digits replied. "Black holes bridge the gap between real space and parallel space just like hyper holes do. And there *is* an upper limit to the mass-energy of a black hole in parallel space. There was even a paper in _The Journal of Hyperspace Physics_ that proposed it, but it used really hard-to-follow tensor math. Do you remember NGC2 +29° 583470?"
All three looked at each other, dumbfounded.
"It was a radio galaxy, spiral class S2, in a supercluster about eight gigalightyears away. The supercluster was precision photographed, all the galaxies in it were assigned New General Catalog 2 numbers, and the observations were shelved. Most astronomy at the time consisted of local star surveys for military purposes, so galactic astronomy took a back seat. 170 years ago the same supercluster was precision photographed again, only this time, no NGC2 +29° 583470. The few people working on it assumed that the earlier photo was bad, that maybe the image of another galaxy from the same cluster had reflected off one of the scope's surfaces and left a ghost double or something, and it was that false image which had been called NGC2 +29° 583470.
But I went back and traced the light path from about 200 light-years back, and the truth was, the galaxy really had been there, and it really had vanished. The black hole at its center reached its upper mass limit. The parallel space version of a white hole opened up in real space, right there in the center of that galaxy, and a spherical wave of utter annihilation expanded out from the galactic center at infinite speed. According to the journal paper, there wouldn't have been anything but total vacuum left within 15000 light-years of the center. Past that, the wave would be tenuous enough that it might leave behind some hydrogen gas at interstellar densities, but nothing thicker than that. The whole effect is supposed to extend outward for about a hundred thousand light-years.
So when I said *everything* is going to end soon, I suppose I was exaggerating. Only the entire Milky Way galaxy is going to end soon. Everything else will be just fine."
The three sat or stood in stunned silence for a long moment. Finally, Ken typed, "You brought us here to tell us that the whole galaxy is doomed, and that there's nothing we can do about it?!"
"No," Torra typed-dictated, "I brought you here because there *is* something you can do about it."
Jennifer: "We can stop a three-millon-solar-mass black hole from blowing up? How?"
Arnold through Torra: "Punch a hole in it. If you detonate a hyper bomb just outside the Schwarzchild Radius, oriented so that the hyper hole ends up facing away from it, mass-energy trapped inside the Radius can get out. It'd be like opening a pressure relief valve."
"That's ridiculous," Jennifer typed, "Everybody knows that nothing inside the Schwarzchild Radius can get out, so how would making a hyper hole *outside* the radius help?"
Arnold through Torra: "Nothing inside the Schwarzchild Radius can achieve *escape velocity*. That doesn't mean that matter or energy trapped inside can't go a *little* ways beyond the Radius and fall back in again."
"And how," Ken typed, "Can you *get* a hyper bomb that close to a black hole, and have remain intact long enough to detonate it, before the tidal gravity turns it into spaghetti?"
Arnold through Torra: "Supermassive black holes have surprisingly shallow gravity gradients. Their gravity may be *strong*, but it's more or less *uniform* close up. It's only the small black holes that have significant tidal forces nearby."
"So, okay," Jennifer typed, "Let's say that this isn't a trick, that you really are the disembodied spirit of Arnold Hasselberg, that Sagittarius A is really about to go wipe out the galaxy, and that the only hope is to poke it with a planetbuster. Even if all that were true, nobody's *ever* mounted a trans-galactic voyage before. There's no way we can build a spacecraft guaranteed to last the 30,000 years it'll take to reach the center of the galaxy, let alone ensure that the phased antimatter warhead and the live crew or semi-intelligent programming will last that long."
Arnold through Torra: "It wouldn't matter if you could. Sagittarius A is
due to reach the mass limit in a matter of months."