Boundary 2: Threshold (18 page)

Exactly what it all meant, of course, they might never know. But it was an amusing thing to find one of the cartoony sketches; some of the Bemmie scientists or researchers actually used the symbol for one of their people as the symbol for Jupiter, along with a symbol meaning "very large"—leading Joe to say, "Ah, yes. The alien timekeeper of the system."

"Huh?" A.J. had replied.

Joe had given one of his fiendish grins. "Obviously, Jupiter was Big Bem."

This had resulted in Joe being hounded from the room.

Aside from Big Bem and a few notations on what Anthony thought might be Io, there wasn't much on this plaque, so he went on to the next.

Several hours went by. Larry finally got up and stretched. "Well, Anthony, I know you've got more endurance than I do, but I'm going to get myself some lunch."

"Oh, is it that time?" Anthony looked at the clock. "I suppose it is. But I started a little later than you, and I want to at least get through this set."

"No problem. Just flag anything you think might be worth looking at."

"Of course."

More plaques. More cryptic sketches and acres of wavelike Bemmie text flowing from outside in, to meet in those upward-sweeping curves.

"Oh, there's something. . . ." Anthony said to himself as the next noteplaque image appeared. Pictures of Saturn weren't nearly as common as those of Jupiter, but the few they had found had sparked rather acrimonious debates among the astronomical community, with even Larry and Anthony exchanging some pointed words occasionally on the subject. The famous rings had existed back then, but the sketches indicated some differences. That the number of clear ring segments would vary wasn't surprising. In fact, depending on exactly how one imaged the rings, from what angle, and in what spectrum, the visible number of segments in the modern era varied pretty widely.

It wasn't the fact that the rings appeared to be separated into three clear sections that was the problem, though. The problem was that several of the discovered sections—including the new one he was looking at—very clearly seemed to indicate that the rings were divided
vertically
as well—into three or four distinct layers, with clear spaces between. If that were to be interpreted literally, there were a number of models that would have to be totally revised.

Most of the rest of the plaque was text, though it appeared that one of Saturn's moons was also marked near the planet. The Bemmies did appear to read from top down, as did humans, and near the bottom was a symbol crossing the centerline, which the linguists had said indicated something like a dash or "continued on next page." Of course, in many cases they were not able to find the next page. Knowing the pattern Jake had excavated in, though, Anthony decided to scout through the ones that were physically nearby this plaque, just to see if the continuation was obvious.

Upon viewing the noteplaque found just below and slightly to the right of the first, Anthony suddenly stopped. The top center column contained the inverted symbol, meaning "continued from," and just below this was a large sketch of some celestial body, a circle with various other symbols on and around it. He looked back at the first one, and saw small symbols next to the marked moon—symbols repeated next to this large sketch. A moon of Saturn, then. Or probably so. Which one? Titan would seem to be the obvious target of interest for anyone in the solar system. A moon with a thick atmosphere and all sorts of activity. But . . . 

No, even displaying Titan's known characteristics in what Bemmie's range of vision would have given didn't seem to produce a correspondence with the markings. The symbols weren't too much help, either. While they'd determined a number of simple symbol conventions that allowed Anthony and Larry to read parts of the astronomical diagrams, too many things were still obscure.

Still . . . that set of symbols, there, toward—he checked the symbology—what would likely be the moon's southern pole . . . that set looked familiar. Very familiar.

Anthony became aware that he needed to breathe. He took a deep breath, realizing that he must have been staring without even breathing at that image for a long time.
This was it.

His first impulse, surprising him, was to call in Larry. He got a grip on himself, already feeling guilty. But this was the reason he'd been brought along. Quickly he checked Larry's status in the on-duty tracker. Still at lunch. He uploaded the application Horst had given him, the last update being only a few days ago. He'd practiced with it many times, but for a minute he froze, unable to remember what he had to do. Then he closed his eyes and took a few deep breaths.

He was feeling intensely guilty.
Focus. Focus. It is not as though we will really be hurting anyone.
He felt bad that he would have to mislead them, but they already had three Bemmie bases. Besides, this new one was so distant that only
Odin
could possibly reach it anyway.

Just a little tweaking. No real erasure. Just some confusion.

Erasing data from the systems being used was an extremely difficult task. There were backups that even Horst's slow-viral approach probably would never reach, unless someone were foolish enough to mount them to the same system they were checking on. So the key was to make it so that they wouldn't bother to check correspondences with the backups until it was far too late. Just a minor transposition of relationships and a very small image edit. The tough part, handled entirely by Horst's app, was making sure that the check data was appropriately modified, so that any examination of the image would not indicate that any modification had been made. In essence, the internal "watermark" had to be modified and the records of the authentication data modified as well, so that all aspects of the system agreed that the modified image was, in fact, the exact original image that had been in the system from the beginning.

If someone were sufficiently suspicious and had access to the backups, of course, they could find the modification easily enough. But with luck, no one would be until it was too late.

Anthony sighed. It was done. He got up, just as Larry came in. For a moment Anthony froze, certain that guilt was written all over his face, that Larry knew he'd been tampering.

"Anything interesting?" the big astrophysicist asked.

"Nothing, really." Anthony's voice sounded strained and flat, totally artificial in his ears. "Time to get something to eat myself, I think."

If his tone was different, Larry didn't appear to notice. "Have fun. Back to the salt mines for me. See you later."

Anthony left quickly, almost bouncing into a wall in his hurry. He had to get this to General Hohenheim immediately.

Then, at least, the rest would be out of his hands.

"Enceladus." The general pronounced the little moon's name carefully.

"Yes, General," Anthony said. "After I reported the initial find, I did continue my research. Since I knew of the connections, I was able to determine a few more facts to confirm the labeling."

Hohenheim nodded. "Very good. I had hoped for something in the Jupiter system, but we are provisioned for Saturn as a possibility. Tell me what makes Enceladus a good possibility, aside from simply finding markings on one of the diagrams?"

Currently, only Hohenheim and LaPointe were present, as the general wanted to evaluate the situation himself privately. Anthony activated the meeting-room display. A rotating image appeared of a mostly white sphere, covered with noticeably varying terrain ranging from small craters to faintly blue–striped cracks.

"Enceladus has been sort of an
enfant terrible
for us astronomical types in the past few decades," Anthony said. "It's much smaller than many of the really large moons like Ganymede, Europa, or our own Luna. In fact, at about five hundred kilometers across, it is quite a bit smaller than our Ceres here. According to many theories of celestial body formation, it should therefore be a relatively static body, a dead rock or iceball floating in space.

"Instead, it is one of only a very few bodies in the solar system with known volcanic activity. It has a surface indicating recent resurfacing—in some areas it may have the most recent surfaces in the solar system." He gestured at the faintly striped areas. "The false-color images overlaid here show what are sometimes whimsically called 'tiger-striping,' but what is significant about them is that they include crystalline water ice—possibly less than a thousand years old, or even newer, given our detection of cryovolcanism—and some organic compounds. There are, however, other areas of Enceladus that are much, much older on the surface."

A cutaway view of the miniature world appeared. Hohenheim frowned. He was of course familiar with cutaway views of Earth and other worlds, but this one was . . . odd. It appeared that the majority of the little moon was cold, but that at one point, near the south pole, it was significantly heated. Totally asymmetric and not at all consistent with anything he had ever seen before.

"I see your expression, General, and you're correct. That's called a
diapir
. The conventional description is that it is lower-density heated material rising to the surface near the south pole. Models of Enceladus have tended to converge on this structure, but what has
caused
the structure you see has been a matter of furious debate." Anthony paused. "Until now."

Hohenheim slowly turned to stare at the grinning scientist. "Are you saying . . . ?"

"Where is the energy coming from, General? That's been the constant debate. Actually, it's been two debates. First, where the energy comes from, because not all models of the tidal forces active on Enceladus appear capable of supplying all of the energy needed. Second, why it's only apparently active in this one location. One can of course come up with all sorts of theories, and I assure you many have. Enceladus is very small, so perhaps it is not as differentiated as a larger body would be. But other evidence argues against this, such as the geological and chemical makeup. Tidal heating of differentiated magmatic chambers—which being liquid would flex more than the solid material around them—could explain the existence of isolated hot spots . . . if the tidal heating were sufficient. But many models don't show the tides as being quite sufficient.

"Yet there is clearly liquid water present in large quantities on Enceladus. Nearly pure water, in fact, as no ammonia or other materials were detected in many of the plumes. This is itself quite notable, as this means the liquid is at a temperature in the Earthly range—at least freezing point of zero Celsius or two hundred seventy-three Kelvin. That is a quite drastic departure in both expected temperature and expected chemistry for that part of the solar system. Much larger bodies, such as Jupiter's Europa, are known to have liquid water beneath the surface, but it was really quite unexpected to find evidence of it on Enceladus."

Anthony pointed again to the off-center southern heated area, the diapir. "The best models we've been able to make, however, have given us this considerable problem—the tidal forces just aren't quite enough. They're fairly close on a cosmic scale, but we're missing a terawatt or so."

"After all this time?" the general said finally. "That is not possible."

"With all due respect, General, it
may
be possible. The aliens used self-repairing redundant technology in a number of ways. If the device or devices in question were intended to operate for some unbounded amount of time, they may have simply continued to do so. Or, as I think more likely, they may have operated for long enough to create the current situation. On an astronomical scale, remember, even sixty-five million years is relatively short. If they had succeeded in creating a diapir or something similar, there is sufficient tidal heating to make it likely that it would still be slowly cooling to this day. We would not notice the change on our timescale. But if they did such a thing, somewhere on Enceladus would be a truly massive installation."

Hohenheim stared at the image, trying to envision it. The distant moon was indeed tiny compared to Earth, but he had spent more than enough time in space to recognize how vast even Enceladus was. Enough power to slowly reshape an entire small world . . . 

He nodded sharply. "Very good. We must begin preparations. Subtly, of course. We must not alert the Ares people on Ceres to our new intentions. I believe I will arrange an apparent recall of
Odin
to Earth. Obviously we will not go there, but preparations for departure will be similar. Very well done, Dr. LaPointe. I am sorry you have been forced into duplicity with your colleagues, but in the long run I hope you will find it was worthwhile. At the least, you shall be the first on the site."

LaPointe managed a smile. "Thank you, General. I appreciate your sympathy. I'd better get back to work, though."

"Indeed. No point in failing to gather any additional data."

As the astronomer left, Hohenheim shook his head. Objectively, he was taking quite a risk. The symbols were undoubtedly those of one of the alien bases, and similar to those for Ceres—that is, the markings of the group of aliens who had lost their battle and apparently been evicted from the system. However, if some device capable of producing such power had been left running, it seemed to Hohenheim fairly likely that it could have destroyed the base when it finally broke down—as any device
must
have broken down after millions of years.

But he was also paid for his intuition, and his intuition said that this was
it
. And, he admitted, there was also the voyage itself. The course would take them through the Jupiter system, the massive planet's gravity well providing them with additional velocity. Hohenheim also knew that in the many months they had been on station, the mass-beam had not been idle. There were more surprises and demonstrations in store for those watching
Odin
, and he was looking forward to a bit of showing off. At the very least, the crew of
Odin
would be famous as the first human beings to ever visit the outer system.