Boundary

by Eric Flint

  Finally, their oxygen running as close to the margin as Helen dared, they returned to Thoat.

  "Well?" Ken asked.

  "Jackpot," was A.J.'s reply.

  Helen's was more dignified. For a while.

  "Captain Hathaway, we have uncovered an alien installation which, though most of it is in the state of ruin you'd expect from planetary as opposed to vacuum conditions, is still in good enough condition to be studied and investigated for . . . oh . . .

  "The place is HUGE, Ken! Way way way way way bigger than the base on Phobos! We'll be digging for years! I'll be working here till I croak of old age! Ha!"

  "You'll need funding," he pointed out, mildly.

  "No sweat. Tell Jackie—no, ask Satya, he's the best horse-trader I know beneath that solemn exterior—to start jacking up those bids. The only condition—ha!—is that they have to send a photographer to Mars. No way I'm letting those paparazzi get near me. And whoever cosmetics companies use. Professional sniffers, whatever. Hound dogs, for all I care. I love this place!"

  Chapter 50

  Three weeks later, Helen was as enthusiastic as ever. Except for Rich, however, the spirits of the other members of the party had dropped some.

  Not much. Just the inevitable amount that would affect anyone who, unlike a field paleontologist or a linguist, didn't regard excruciatingly patient study to be the quintessence of professional pleasure.

  "It's pretty run-down," A.J. grumbled one evening over their communal dinner in Thoat. "Yes, I know that's to be expected. Even as well as the Bemmies built and even with Mars' atmosphere and stable geology, sixty-five million years is sixty-five million years."

  "On Earth, not one percent of this would have survived," Helen pointed out.

  A.J. half-glared at her. Not because he disagreed, but simply at the insufferably cheery way she said it. "I know," Helen added, grinning at him. "What do you expect from a grubby bonedigger, o ye high tech wizard?"

  A.J.'s good spirits returned, within seconds. However much the state of decay of the ruins at Melas Chasma frustrated his professional desire for the sort of things he could investigate thoroughly with his methods, as he'd been able to on Phobos, the personal side of his life was as good as he could ask for. He loved Helen, at any time. Helen in the best mood he'd ever seen her—day after day after day—was a pure delight to be with.

  The dinner finished, Helen kicked off a general discussion. "I've come to the conclusion that this base isn't at all like the one on Phobos. But I'd like everyone else's assessment."

  "Agreed," Madeline said. "But I don't know if you're seeing the same things I am. What are you seeing?"

  "Well, the most obvious is that this base was fully intact. All the damage we're seeing is from time passing. There was no damage from bombardment or weapons of any kind, as far as we can see."

  Helen took a bite of the small fruit ration bar that constituted dessert. "We've found no Bemmius corpses here—or corpses of any kind. Plenty of noteplaques, but all of them neatly stored away, not scattered like they were on Phobos. Everything here is neat, in order, and a lot of it is completely empty. Like a house someone just put up for sale. They evacuated this place at their leisure, either well before or well after the bombardment. What are you seeing?"

  "Layout and design," Joe said promptly. Rich and A.J. nodded.

  "The purpose of the bases was entirely different," Joe amplified. "The design of the one on Phobos, as far as I'm concerned, is clearly military. We've found firing ranges, tons of hand weapons, indications that much larger weaponry was once in place, rooms that are hard to categorize as anything other than barracks, so on and so forth."

  A.J. picked up the thread. "By contrast, down here . . . Well, it's really hard to analyze some things, since they have—as you say— stripped a lot of the equipment out. Something the Phobos residents apparently never had a chance to do. But from the wiring, pipes, layout of rooms, and other things, it looks to me—and most of the engineers up on Nike agree—that this was more of a research institution."

  "What about the Vault?" Rich asked.

  "That is a puzzle," Joe said. "One that we'll have to solve. If we can figure out how to get into it."

  The "Vault" was located near the center of the base, from what Helen and A.J. had been able to ascertain so far about the base's layout. It was a huge structure that was made of the most stubbornly tough materials the Bemmies—or whoever had built the base—had owned, supported by massive reinforcing columns three times thicker than any support members in the rest of the base, and sealed off from it with only one connecting corridor and doorway.

  The Vault was so clearly separate and massive as to be intimidating as well as mystifying. There was even some evidence around the doorway, based on slight irregularities of the nearby walls and floor, that over the past sixty-five million years the miniscule geologic activity of Mars had moved the rest of the base slightly while not affecting the Vault. The doorway in question didn't just look like a vault door, either—it appeared to actually be a vault door, in terms of thickness and toughness. In point of fact, there was considerable debate about whether to call it a door, at all. There was no sign of ordinary opening mechanisms, although the seam where it fit into the tubelike entrance hall for the Vault was clear enough.

  "It's as though they sealed the door shut with no intention of ever opening it again," Madeline mused.

  "'And so,'" A.J. said in a sepulchral voice, "'they placed a seal upon the Tomb and all manner of enchantments, that that which lay within would never again—'"

  "Shut up, A.J.!" came a chorus of voices.

  "You know . . ." Rich said after a moment. "A.J. might be onto something this time."

  "Huh?"

  Rich laughed. "I don't mean that some nameless eldritch horror lies beyond the door. I mean that it might literally be a tomb. Like a pyramid, you know. What if whoever they were had a sort of religious structure to their civilization, and one of their leaders died here?"

  "But wouldn't that be awfully wasteful?" Joe objected. "Would that make sense for a civilization this advanced?"

  "At the time," Rich countered, "Egypt was probably the most advanced civilization in the world. And you're trying to make sense of things based on our point of view. Sure, so far, it does look as if the Bemmies were rather like us, in many ways. But we don't know for sure that the Bemmies built this base, although the ergonomics of what's left does look rather appropriate for their species. And even if it was built by them, we don't know what their culture was like. If they were having a war—which all those crater targets damn well seem to indicate—it might have been religious in nature. Anyway, it's just a thought."

  Madeline looked at one of the images of the enigmatic sealed entrance which were lying on the table. "Well, there's only one way to find out."

  Joe smiled. "That's my delicate lady love. Her favorite word. Boom."

  Despite A.J.'s occasional references to Things Man Was Not Meant To Know—Joe's witticisms were even worse—Madeline and

  A.J. spent the next few days trying to figure out the best way to get through the doorway. In the end, sure enough, the only workable method they could think of involved one form or another of demolitions.

  That was something they approached reluctantly — especially Madeline, despite Joe's wisecrack. The concepts of high explosives and underground exploration did not generally combine well, and Madeline knew a lot more about both subjects than anyone else on Mars did.

  However, there was little doubt that they were in fact going to give it a try, since they couldn't figure out any other way to accomplish the task. The Vault represented a huge unexplored area of the base and potentially the most valuable one. If it were a tomb of the sort Rich had speculated about, one of the most common features of such tombs on Earth was that they were filled with all manner of valuables and items meant to accompany the owner to their afterlife.

  Joe did suggest that it might be their dump, especially for rad
ioactive waste, but even that might provide valuable clues to their technology and society. In any event, after sixty-five million years all the high-level radioactives would have decayed away. Their suits would provide more than adequate protection if that turned out to be the case.

  "Charges set. I'm coming down." Madeline's voice was calm and businesslike, showing none of the tension Joe knew she must be feeling. If something went wrong, she could collapse enough of the base to make the Vault unreachable for years, if ever.

  Having finally been able to come along again after more than a month convalescing, Joe watched the opening at the top of Melted Way for her small suited figure to appear. For safety, they would trigger the detonation from outside the Ice Cavern, making sure that even if the worst-case scenario happened, none of them would be caught in it.

  A few minutes later, he saw Madeline making her way down the path, and went to meet her at the bottom. His leg ached slightly and was still in a cast below the knee, but at least it was now functioning.

  "How many did you set?"

  "Five. I see no point in trying this halfway. Those alloys, composites, whatever they are, they're just tough as hell. Either I can blow that door, or I can't. If I did it right, it shouldn't make much difference in the risk as to whether I used one charge or all five."

  "Still," A.J. said, "five? We just want to blow the door off, not vaporize it."

  Madeline peered into the distance and spotted him waiting at the other side of the cavern. "Actually, I just want the door gone. If it's in one piece or a thousand isn't critical, as long as I don't damage too much behind it."

  "I just hope you got your designs right."

  "I checked them several times," Madeline said. "And the more I looked at that door, the more sure I was that I was going to need all of them."

  The explosives had been designed as shaped charges, with geometry and backing to direct virtually all of their force along the door seam. With incendiary materials—basically thermite, that venerable mix of iron oxide and aluminum which burned at over twenty-five hundred degrees centigrade, and would do so even underwater or in Mars' almost nonexistent atmosphere—to hopefully continue the cutting, burning through anything that remained.

  Madeline insisted that Joe cross the cavern first, while she and

  A.J. served as his spotters. Then she scurried across herself. By now, crossing the cavern was almost routine. Experience had shown them that the stalactites only dropped pieces on rare occasions. They still maintained the spotting system, but no one had ever actually had to use it to avoid being struck.

  They would trigger off the charges from the relative security of the floor of the rock crevice. Hathaway had almost insisted that they return aboveground altogether, but eventually they'd talked him out of it. The climb up the crevice was the slowest and most arduous part of the trip.

  Fortunately, Chad Baird had sided with them in the dispute.

  "That's all rock, Captain, with no ice or loose material to be shaken down. The charges Madeline set aren't that big—and there's all that empty space in the cavern to absorb what little shock waves get transmitted through the thin air. They'll be safe enough there."

  Grudgingly, Hathaway had finally agreed. So, now, everyone was waiting on the crevice floor.

  "Ready?" Joe asked. At the acknowledgements, he glanced at his display. "Okay, Madeline. Set it off."

  The image of the Vault's sealed door, transmitted down A.J.'s line of bread-crumb transceivers, abruptly fuzzed and vanished in a fog of smoke and dust. Through the veil, five blazingly blue-white smears of light could dimly be made out, the incendiaries continuing their work. Joe imagined he heard a faint thud, but knew it had to be his imagination. The smoke became thick, but the most important thing about the image was that it continued to exist.

  "No collapse. None of my sensors are showing any sign of movement, either," A.J. reported with satisfaction. "Let's head on up. By the time we get there, it should be done."

  "No, let's wait until it's finished," Helen said. "I don't want to listen to Ken hollering at me afterward."

  "There's no point in rushing, anyway," Madeline chimed in. "The wreckage will stay very hot for a while, and these suits were definitely not made to take steel-melting temperatures. Keep an eye on things in IR and make sure you don't touch anything without the right tools."

  "Don't teach your grandfather how to use sensors," A.J. retorted. "I can see better in three spectra at once than you can in one. And I understand it all."

  "To understand is not to act. I've seen you act without thinking. That was my caution."

  "She's right, A.J.," Joe said.

  "Well, of course you're on her side."

  "I don't recall being the one who decided to run into burning buildings with nothing but balls, a blanket, and a VRD."

  "Okay, okay. I get the point. I'll wait until I'm told it's safe before grabbing anything."

  Eventually, Helen gave the signal. "Come along, people," said Madeline. "And everyone take your chunk of ice."

  Even Bruce was there this time. It had become clear that aside from certain areas—which were now braced—it was reasonably safe to be underground here, and no one wanted to be left out of the chance to enter the Vault for the first time.

  The smoke had mostly settled and was flowing away through the base, many of its components being heavier than anything the thin Martian atmosphere could support. By the time they finally reached the Vault, the air was almost clear. The sealed door still smoldered and glowed in places.

  Madeline took her block of ice and motioned everyone to the side. Then, very gingerly, holding it only by her fingertips, pressed the ice block into one of the holes.

  Steam blasted out, accompanied by high-pitched crackling, hissing noises. Madeline held the ice steady but made no effort to push it harder into the hole.

  As her chunk melted away, the others methodically repeated the process, using thermal shock to hopefully finish the job of weakening the door—and, incidentally, cooling it to a workable temperature.

  The cautious and methodical approach had been dictated by Joe. To something of his satisfaction, it was A.J. who graphically demonstrated why it was the right method. A.J. pressed his first chunk of ice into its hole with vigor and determination. The chunk of ice was blown out of the hole almost on contact, ripping itself out of the sensor expert's hands and continuing on, a hurtling twenty-kilo missile that could have hurt someone, if it hit the wrong way.

  "Okay, Joe, you were right. That would have been bad."

  "Damn right it would, Mr. Seat-of-the-Pants."

  Finally Joe decided they'd done all they could, and they began attaching cables to the door. Most of the door appeared to have been eaten through, according to A.J.'s Fairy Dust examination, and the remainder of the seal area was cracked.

  Jack the Ripper was once more reconfigured, this time to a winch configuration. A block and tackle had been rigged using cable of the same composition that Thoat's winch used, and Jack was braced and locked to one of the main support columns. Even with bracing methods and mechanical advantage, the cable was far stronger; Jack would break long before the cable would.

  It was something of an anticlimax that after all that preparation, the Vault door moved almost as soon as Jack started pulling. Within a minute, the heavy drone had dragged it open far enough to allow the little party to enter the area it had formerly sealed off.

  "I guess you do know your explosives," Joe said. "But then, I always knew you were dynamite."

  Madeline actually giggled.