Boundary 1: Boundary (50 page)

"I'll kill her," Helen snarled. "And you're next!"

"Under the circumstances, that's a pretty idle threat," Ken pointed out, as cheerily as ever. "Jackie also wants to know what you'd like for your birthday coming up. She warns you she can't afford anything fancy, even if you are on the verge of becoming richer than Croesus."

"I want a cave in a desert somewhere!" Helen half-shouted. "Where I might get my privacy back!"

Ken laughed again. "Why bother? Just stay on Mars."

Helen's eyed widened.

And widened. Her stomach paused in its headlong flight.

She looked at A.J. He was sitting nearby in the rover, obviously doing his level best to keep from laughing himself.

His level best wasn't nearly good enough, so far as she was concerned. "One chuckle out of you," she hissed, "and you can look forward to a completely celibate stay on Mars."

That sobered him up, some. The threat wasn't idle, either. Not since they'd set up the bubbles and had some personal space again.

"Wouldn't think of it," he managed to get out.

"Good."
After a moment, though, her glare started fading. "What do you think, A.J. Is it possible?"

He shrugged. "Maybe. It's certainly feasible, from a technical standpoint. The real question—what else is new?—will be the funding. At a guess, I'd say that depends mostly on what we find—or don't find—at Target 37. If there's a real dig to be done there . . . You know what I mean. A major one."

"A real dig," she mused. "A major dig. Major digs take
years
. . ."

Somewhere far to the south, Helen's stomach wheeled around and start flapping back.

Since A.J. managed to keep from chuckling—barely—Helen didn't carry out her threat that night. Rather the opposite, in fact.

"I love you," she murmured, contently exhausted and lying sprawled across him. "Would you stay here with me?"

"Don't ask silly questions. I came here looking for one dream, and found two. Of course I will."

She could feel a suspicious rumble, with her palm spread across his bare chest. "What's so funny?"

He was practically choking, now.

"What's so funny?"

"Well, I just got to thinking about funding. And it occurred to me—"

"You even finish that sentence, mister—!"

"Let's see what we can find," Helen said. "And stop whining, Joe. Paleontologists always start work at the crack of dawn, you know that. It's not my fault—"

She broke off abruptly, realizing she might be treading onto delicate ground.

Joe wouldn't be coming with them, naturally, with his leg broken. He and Bruce and Rich would stay behind in the camp and finish setting it up, while the other three started scouting for Target 37.

Helen had decided to leave Bruce and Rich behind also, because neither of them had any skills that would be of particular use in this initial scouting expedition. A.J. was coming along for his sensor expertise, which would almost certainly be needed to find ruins that were sixty-five-million years old. Helen, of course, was the only one except Joe with real experience at this work. Finally, she'd chosen Madeline because three would be safer, and Helen had a great deal of confidence in the security official's general competence.

So there was really no reason for Joe to be up this early. Helen assumed that Madeline had woken him up when she arose. Which wouldn't have been hard to do, since she'd been sleeping with him.

Madeline Fathom had apparently decided that their safe arrival here was an omen, or a signal—or whatever it was that mattered to her Inner Self, which Helen still found somewhat mysterious. As soon as they'd started erecting the bubbles, she'd quietly and matter-of-factly explained that she and Joe would share one, so they only needed to put up four instead of five for living quarters.

The look on Joe's face when she'd made that announcement had been . . . priceless. It was blindingly obvious that it had come as a surprise to him, too.

The look on his face this morning, on the other hand, was that subtle, hard-to-define-but-unmistakable expression that characterized civilized men trying to suppress their cruder impulses. A combination of smugness and exultation kept under tight restraint, so that the barbarian within didn't start leaping about the landscape and shouting "Boy, did I
score
last night!"

But he also looked inexpressibly happy, so Helen forgave him his male sins. When all was said and done, she approved of Joe Buckley. Very highly.

"It's not
my
fault," Madeline said, smiling that million-dollar smile. "He insisted I wake him up before we left. I felt bad about it, since I didn't let him sleep much in the first place. Broken leg be damned, he got no mercy from me last night."

Okay, then.
Not
delicate ground.

Putting on his helmet, A.J. glanced over at Joe in admiration. One of the things he'd always liked the most about his friend was his very solid ego. It just didn't seem to faze Joe at all that he'd gotten himself a woman who could probably outdo him in almost anything except engineering and cooking—and maybe not the cooking. At this point, A.J. wouldn't really be surprised to discover that Madeline Fathom was a Cordon Bleu graduate, on top of everything else. She seemed to pull out new skills the way a magician pulled rabbits out of a hat.

"A.J.?"

He suddenly became aware that Helen was speaking to him. "Huh?"

"I said, are you ready? What's up?"

"Just thinking, taking up too many processing cycles to detect your inquiry. Sorry, yes, I'm set. Got it all ready."

The three of them stepped into
Thoat
's airlock and cycled out onto the Martian soil. A.J. took a deep breath, as though he were stepping outside a mountain cabin and breathing in the air. The magnificent view called for some such gesture.

The orbital pictures had shown the area of Target 37 as being near, or even right below, a whitish chevron-shaped marking next to a small gully or canyon on the floor of the Melas Chasma area. Such images are deceptive, however. A.J. was struck again by just how deceptive they were as he glanced to his right.

There, about a quarter of a kilometer distant, was the edge of the so-called gully.

The term was a little ridiculous, he thought. The sheer scale of Valles Marineris warranted calling it a gully, perhaps, but on Earth it would be a canyon in its own right. More than three kilometers across at its widest, it ran a curved, slightly zigzag course for more than thirty klicks before petering out. Even here, where it narrowed drastically, it was several hundred meters wide and hundreds deep, red-pink-gray rock walls plunging down into a shadowed crease in the immensity of Mariner's Valley.

As they had been the first humans to reach the gully, they felt they had the right to name it. And since they'd done so through the services of the huge rover, they'd unanimously decided to name it "Thoat Canyon." Barring any official objections later, of course; but, under the circumstances, that was hardly likely.

The lighter soil, not so clearly whitish up close, had strong concentrations of salts in it. For reasons that were unclear to A.J., that news had been very exciting to the areologists on
Nike
and presumably on Earth. Small rises and cliffs surrounded the area to the north, where A.J. was facing, and to the left.
Thoat
had needed to round the southern part of its eponymous canyon and drive northwest to reach their current position, and he could see their tracks still visible in the sands to the south. The wind would undoubtedly erase them eventually, but for the moment he suspected that most of their course across Mars could be traced from orbit with a good enough telescope.

"Where are we going?" Madeline inquired. "You were running your sensors most of the night, right?"

A.J. sighed. "Much as I hate to admit it, I am at least partially defeated at the moment. You know how some of the weird alloys and composites the Bemmies had on Phobos kept messing with my sensors, from GPR on through just about everything else? Well, there's one big-ass chunk of this base that seems to be made out of that same stuff. I can't see anything past it—which means on the other side of the base, under it, and partly to the sides. And I can't drive
Thoat
around to check from different positions, obviously."

"So you got nothing?"

"I didn't say
that
. I just didn't get nearly as much as I hoped to get, and there's nothing that looks tremendously promising. We'll have to scout around the base perimeter—which is pretty darn big— for the next few days with portable units, if we want to get data on the rest of the area. I can say this much: if we're going to find entrances, that ridge"—he pointed to the fifty-meter-high cliff half a kilometer away—"is our best bet. Remember how we found the entrance to Phobos Base? Well, the same problem we faced on Phobos is here, only about a million times worse. Any opening that was standing on regular open ground will have filled in completely. I'm not sure if you can get solid rock out of just wind-blown stuff settling. But, if you can, after sixty-plus million years any openings that got filled in might be rock by now. Even if not, they'll have been completely buried eons ago. So, just like on Phobos, we have to look for caves or cracks that might have stayed open that long."

Helen nodded. "Makes sense. We do have one thing in our favor, too. Mars is geologically stable, compared to Earth. There's almost nowhere on Earth you could go which would have a chance of retaining any geological structures that old. Especially not things like caves and tunnels. But Mars has less gravity to collapse things, a lot fewer earthquakes, and—so far as we know, at least—no mechanism like plate tectonics to refurbish the surface every few hundred million years."

"Pretty much," Joe agreed, having been listening in. "It looks like it tried to go for that model around the time Olympus Mons got started. But without the ability to keep a liquid mantle, that was doomed to failure."

"The ridge it is, then." Madeline set off, the other two following. Close on A.J.'s heels came one of the two automated equipment and sensor rover carts they'd brought with them. Land-bound equivalents of the Faeries, essentially. It was loaded with portable GPS and other sensor equipment, plus rock-climbing gear.

"Back off a bit, Willis," he told it. Willis obediently fell back a meter or so farther, making A.J. feel less crowded.

Fifty meters was nothing compared to the main cliffs of Valles Marineris visible in the distance. But, up close, they were still formidable walls of red-gray stone, fissured and seamed, covered with the dust of years beyond count that sifted slowly down the rock face.

"Here's a hole big enough," A.J. said. He shone a light down. "Seems to go a fair distance, too."

After crawling into it for several meters, however, he learned the rough-floored tunnel narrowed to nothing. "Dry hole. Well, I didn't expect to find it right away."

"A.J., Madeline and I will keep looking for good possibilities in this rock face," Helen said. "You're wasting your skills doing that. Anyone can crawl into holes. See what you can get on GPR and your other gadgets."

"You got it."

A.J. began removing the equipment from Willis and setting it up. At least in this new location he'd have a different angle on the base and might get some shots at areas that had been completely obscured before.

Unfortunately, his repertoire was relatively limited here. The surface was heavily covered by drifting dust, so using acoustics would be basically useless. The Fairy Dust wouldn't help here, really. GPR and related RF approaches were pretty much all he could use without the ability to bore into bedrock. He could use a synthetic-aperture type approach to increase resolution and sensitivity, though, if he moved the GPR setup.

For the next several minutes he was busy reconfiguring Willis and setting the GPR unit firmly on the little rover. "There, that's got it. How are you people coming?"

"Lots of little holes and big holes," came Helen's slightly breathless voice. "But nothing promising, so far. You?"

"About to start getting us some more data." He started Willis and the GPR unit running. For the next hour he paced the sensor platform as it sent regular pulses into the Martian soil and bedrock, recorded the returns, and sent them to
Thoat
's main systems to analyze. He could, of course, have had
Nike
do the analysis—with the satellite network, they were never out of communication with the interplanetary vessel—but he liked doing things with what he had. And this analysis wasn't particularly difficult.

It was, however, increasingly disappointing. The more the returns came in and were processed, the more clearly the base on this side was delineated. And the less and less likely it became that there were, or ever had been, any entrances—natural or
Bemmius
-made—in this area.

Finally he shook his head. "Ladies, give it up. There's nothing to find here."

"Damn," said Madeline without rancor. "I was hoping we could find something fairly quickly—because I certainly don't like the idea of trying to dig our way down to the thing. Well, we still have more perimeter to check. Maybe tomorrow."

She started making her way down the backside of the ridge, which sloped much less steeply on that side.

It wasn't until a few moments later that it registered on A.J. that Helen hadn't responded. For a moment he almost panicked, until he saw that she was at the top of the ridge, looking outward. Maybe just admiring the view. It'd be a while—a long while—before any of them started taking that view for granted. Compared to Valles Marineris, the Grand Canyon in Arizona was a ditch.

"Helen, you okay?"

"Hmmm?" Her voice sounded distracted. He could almost see her expression; it was the one she wore when she almost had a problem solved. "A.J., what do your GPR scans say about the geology?"

"Geology? Well, I'm not an expert, but basically, um, we've got the top layer of crap, something that I guess might be sorta-sandstone under the dust and debris, then a bunch of denser stone, and something else under that. The sorta-sandstone isn't very thick, the denser stone is thicker—maybe fifty to a hundred meters total in this area, though I get vague indications it tends to be even thicker off to the west. The denser stone makes it real hard to see through past that, and I have to be honest that I wasn't using stuff that would look down past twenty to fifty meters anyway. Any tunnels we're looking for have to come nearer the surface than that. Why?"