Analog SFF, June 2007

by Dell Magazine Authors

  What I'd been looking for was a nice sloping rampway, but everything was surprisingly steep. If I slipped and started tumbling, it was going to hurt, even in low gee.

  Brittney had figured it out. “You're going to climb out?"

  "Yep."

  "You're going to burn a lot of air."

  "Yep."

  I'd said she wouldn't like it.

  * * * *

  It wasn't too bad at first. Underneath, the mountain might be made of solid ice, but its surface was covered in fallen rocks and coarse, soil-like material. The result was a lot of nice steps. Steep but manageable.

  But cryolava apparently comes in layers, just like ordinary lava. As I climbed, I encountered cliffs, like tiers in a wedding cake. Each time, I had to traverse loose scree, looking for breaks that offered climbable chutes. Weird, weird, weird. Basalt produces such landforms. But ice?

  Several times, I had to resort to hands to pull myself to the crest of a particularly steep layer—only to find yet another tier above. The higher I climbed, the smaller the rocks became and the more they tended to roll at the slightest touch. Once disturbed, they went forever, tinkling in slow-moving avalanches until they disappeared over the lip of a cliff.

  "Why the hell does everything move like this?” I exploded, at last. The climb was taking forever, and each time I had to fight bad footing, I squandered oxygen. “Why doesn't the low gravity make it more stable?"

  "The angle of repose is the same as on Earth,” Brittney said. “That's the steepest slope at which you can pile rocks without having them start to roll. When you run the math, the force of gravity cancels out, at least on first order. It's not what they call intuitively obvious."

  "Intuitively obvious?"

  "A phrase. For your benefit."

  Like hell it was. Brittney's as capable as I am of being surprised. The only difference is that for things like this, she's really good at figuring out the answers.

  * * * *

  It took twenty-six minutes at slightly better than nine METs to reach the top. A nasty dent in my oxygen supply, for essentially no progress toward the canister. Other than reporting the number, Brittney said nothing. I said nothing. Had it been worth it? Time would tell. Still, I felt a new lease on life: an emergence from claustrophobia into a realm where you could at least see the horizon.

  We were higher than I'd expected; apparently the cryovolcano humped up inland. Brittney's alligator ridge was somewhere below us, unrecognizable from this angle.

  "This thing's big,” I said.

  "Yes. Out here, its edges are chewed up into a lot of ridges and gullies, but from what I could see on our way down, its interior might be what the volcanologists call a pancake dome. Some of those are more than a hundred klicks across. If we're lucky, the canister's somewhere up on top."

  That wasn't as reassuring as she meant it to be. “And if we're not?"

  "It's down in some canyon. Or off in more sand dunes on the far side."

  Not reassuring at all. The only way we were going to find the canister was if we got close enough for Brittney to talk to it via the suit's short-range com channel. That was going to take line of sight. If it was down in a canyon, we could walk right by it without knowing. If it was far out in the sand, we'd never reach it before I ran out of air.

  Well, there's one thing about life as a spacer. I'd long ago learned that when things go sour, you concentrate on the things you can do. As for the others, you either try to pretend they don't exist or pray about them, depending on your orientation. Me, I wasn't in the praying camp. I'd presumed Brittney was the same, but you know, I had no idea why. Another thing we'd never discussed.

  Nor would we now. “Which way?” I asked.

  The hesitation was longer than ever. Maybe she was praying.

  "Best guess,” I said. “The only wrong answer is ‘stay here.’”

  "Thanks. Really. This is awful.” She needed to be able to truly sigh. Or gulp, or something like that. “Okay, do a slow three-sixty. It was hard to keep my bearings down in that canyon. And climbing out was worse."

  I complied. What I could see of the pancake dome was a broad mound, forming the horizon in the direction I'd been calling inland.

  "All right,” she said. “Look a bit to the left of the highest point. That's it. Let's go that way. The good news is that I think you climbed several hundred meters. The elevation won't hurt when it comes to getting a signal from the canister. But we've got at least sixty kilometers to go. And it could be a hundred."

  Sixty klicks. In one-seventh gee, but with spacer-weak muscles. At least the footing was good. The ridge top was smooth, as I'd hoped, almost as though it had been wind blasted. Too bad Brittney hadn't thought to tell me about pancake domes before we'd started walking the wash. Washes aren't the only highways.

  * * * *

  Ten minutes later, I was trying to remember how long it had been since the last time I'd run. Running is impossible in zero gee except on a centrifugal wheel, and not only was my ship too small, but wheels always make me feel like somebody's pet gerbil. I preferred stationary cycling. Unfortunately, that doesn't use quite the same muscles.

  That said, I was making good time. “Twenty-one klicks an hour!” Brittney sang out. “Seven-point-eight METs! That's 2.7 kph per MET. Is that the right unit?"

  "As good as any.” I'd only given her the job to keep her busy. “What really matters is that I'm doing a pace at which I can carry on a reasonably normal conversation."

  "Doesn't that waste air?"

  "No. Where'd you get that idea?” You often find that old myth on vids, but other than the small amount of energy it takes to use your vocal cords, talking simply moves air in and out. The oxygen's still there.

  "From Ship,” she said, vaguely. She always referred to my tug's computer that way, as though she hoped someday to positive-think it into sentience. Thankfully, she hadn't succeeded. Two Brittneys would have been one and a half too many. “How do you know so much about this stuff?” she added.

  Damn. I'd forgotten about her idea of normal conversation. I stalled, trying to figure out whether I was willing to talk about this.

  "Have you ever heard of ‘To Build a Fire'?” I asked eventually. Silly question. I was talking to an AI. Why would she care about things like that?

  But I really hadn't spent enough time thinking about what it meant to be a sentient AI, with nothing much to do at night but scour Ship's library and hope I didn't die in my sleep. “Yes,” she said. “That's the Jack London story about the gold prospector who freezes because his hands got too cold to strike a match."

  I was impressed. “Right.” I paused. Why didn't I want to talk about this? Just because it was a reminder that we might die, too? That was impossible not to think about. “Okay. The part that struck me was the image of him collapsing, unable to take another step. I kept thinking, how can you not be able to take one more step? And if you can do that, why not another, and another?"

  "Uh, there's an obvious flaw to that reasoning."

  "Of course.” I knew that, in theory at least. “But there were a few years when I was obsessed with endurance.” Or, at least, with the idea of endurance. “I kept trying to find that limit in myself: the point where you really can't take another step."

  Long pause. “Did you?"

  "No.” Not in six marathons and a couple of Ironman triathlons. Not in a three-day, 1,200-kilometer bicycle race. I'd found times when I didn't want to go on, but none when I couldn't.

  "Good."

  It crossed my mind now that maybe what I'd really been obsessed with was whether my parents might have been able to will themselves to live another second. Or a femtosecond. And then another, and another after that, until finally they were rescued. That the only reason they weren't with me now was that they hadn't wanted it enough. Silly, but that's how it is with obsessions. Along the way, I'd picked up quite a bit of exercise physiology, though I couldn't see how it would help me now. The marathoning was a differ
ent matter. I might be out of practice, but I was hitting my second wind. Maybe I'd just been tired from the long scramble to the ridge top.

  "Two point nine kph per MET,” Brittney said. “Good job."

  * * * *

  The running remained easy, and gradually the ridge merged into a flat, uninteresting plateau—though under the circumstances, uninteresting was a great word. So was flat. While going downhill would be easier, the longer until it happened, the greater the chance I'd still be in uninteresting terrain when I found the canister. Brittney said we'd covered thirty-four kilometers since the sand dunes. If our luck held, we might just make it.

  She didn't try to start another conversation. Other than progress reports and a periodic “How's it going?” she pretty much left me to my thoughts. Normally, I'd have appreciated that, but at the moment, I wasn't too fond of them. Too much unanswerable history. Not enough ... not enough what? It wasn't as though I hated it out here on the dark edge of the Solar System. The scientists were right; it's a pretty cool place. Though I'd rather not die here.

  "Slow down,” Brittney said suddenly. “And try taking shorter steps."

  "What?" Even though I'd never been fast enough to win one of those long-ago races, I'd taken pride in coaxing my body to the best it could do. And now, Brittney—a bunch of code who had no idea what running felt like—was telling me I was screwing up. “I know what I'm doing."

  "Maybe. But you've been gradually speeding up, and your kph per MET has been dropping. Not a lot, but enough to reduce your range by several klicks."

  I'd not paid much attention to sports since I'd left Earth. Now, as I forced myself to comply and not argue with her, I wondered what the rules were about AIs in the Olympics. If Brittney could do this by dead reckoning, what could she do with real data? In fact ... “How the hell can you measure my speed?” I asked. Or distance, for that matter.

  "Retroactively. Any time we reach a landmark, like that big rock over there, I can tell how large it is. Then I rewind to when you first saw it and calculate out how far away it was. I also count steps. It's not super accurate, but it ought to be good to within about ten percent. More importantly, it should be pretty consistent, so I can tell if we're speeding up or slowing down."

  "Very slick. I had no idea you were recording all of that."

  "You never know when something might come in useful.” She gave me another of those odd pauses. “Like Jack London. It's nice to know more about what makes you ... you."

  * * * *

  The run continued. Monotony, with life and death hanging in the balance. And increasingly, pain. Not long into the second hour, my second wind deserted me. Balance required more concentration. Sweat lathered the inside of my skinsuit before my body heat vaporized it and drove it away. I felt as though I was running in a sauna, which was weird, given how cold it was only millimeters away.

  I was also increasingly aware of the density of Titan's atmosphere. It magnified every puff of breeze to buffeting force. The storm had abated considerably, but it still felt like running through molasses. I slowed again, and felt oddly reassured when Brittney didn't comment, one way or the other.

  At the two-hour mark, I broke to a walk and sipped some water. Three-fourths gone. The last part of this trip wasn't going to be fun. While I was at it, I took a few swallows from the suit's food tube. It was another of those things I'd not had the opportunity to test before my life depended on it: I had no idea what it was. Brittney had searched the specs, but come up blank; the food was whatever the suit manufacturer had filled it with in the factory. All I knew for sure was that it was sweet and had a near infinite shelf life. Sweet was good. Not having to worry about food poisoning was better. But the syrupy goop was running out quicker than the air or water.

  Brittney didn't comment directly. “You'll make it,” she said instead. “You're doing good."

  For some reason, that bugged me. Maybe because however well I was doing now, good wasn't a likely prospect for the future. There's a huge difference between taking another step, and doing so quickly. In my endurance-envelope-chasing days, I'd sure as hell learned that one a time or two.

  "Wha'd you do, read a damn cheerleading manual?"

  Brittney was silent for quite a while. Long enough that I could feel my breathing rate drop to something more reasonable. Long enough that I wondered if I might have knocked the perkiness out of her forever. Long enough that I again found myself wondering what life looked like from her perspective.

  "Why did you go to space?” she asked eventually.

  "Because Earth was getting too filled up,” I said, though it wasn't really true. That's why I'd left Jupiter. I liked to think it was also why I'd left Earth, but the world's population had been stable for decades. I'd just given up trying to fit.

  "So if you don't like company,” Brittney said, seeing right through my pretense, “why did you get me?"

  Because at the time, she'd just been an AI. An “it,” not a “who.” I had no idea she'd be the one in ten thousand that went sentient.

  "Not sure,” I said. “You do calculate a mean trajectory."

  It was an invitation to shut up, but she ignored it. “I don't do anything of that type that Ship can't do."

  "Well, Ship got clobbered by a meteor.” Along with the radio that might have called for help, and about ninety-five percent of everything else useful.

  I glanced at the suit's wrist chrono. I'd been walking for five minutes. Five-minute walk. Ten-minute run. That was a good formula, for as long as I could keep it up. “Time to run."

  Again, she didn't argue: didn't suggest that six minutes’ rest might be better. Or four minutes. Or five minutes and one second. In fact, for the next hour or so, she again didn't do much but keep me posted on numbers: METs and oxygen and how much farther we could go before I gasped my last—things like that. Why the hell had I gotten her? It didn't take an AI to do that stuff; a much simpler symbiote could do the same. And it for sure didn't take a sentient AI, though I have to admit I never thought of that prospect when I wagered everything to secure her.

  * * * *

  The rest breaks were getting longer, the runs shorter. We'd crested the summit and were going down, but I wasn't going any faster. My efficiency was dropping: 2.9 kph/MET, 2.8, 2.5, and most recently, 2.2. My legs felt like lead, my breathing was coming in ragged pants, and the run/walk cycle had dropped from ten on/five off to two on/one off.

  "How far?” I gasped for what must have been the tenth time in the last hour. I wasn't sure which was worse: not knowing, or discovering I'd not even covered another half klick. I couldn't believe how hot it was in the skinsuit. The damn thing was built to keep me warm on the dark side of ... well, Enceladus or pretty much anything else airless and cold. It could also reflect sunlight and keep me pleasantly temperate in the full glare of Earth orbit. What it was not designed for was continuous hard work.

  "Coming up on sixty-two klicks,” Brittney said. Anywhere from three-fourths to half of the way, depending.

  "Air?” I'd not asked that for a while. I could always just check the gauge, but it was too easy to imagine big changes.

  "Sixty-four point three percent down."

  In other words, if my chute had drifted a hundred twenty klicks, I was dead meat. If it had been under a hundred, we might still make it if I didn't lose more efficiency, which wasn't likely.

  * * * *

  Sometime later, I checked my suit chrono, but could no longer remember when I'd taken my last walk break. I felt giddy, floating for oddly prolonged intervals between strides, then striking heavily and off balance. I concentrated harder. If you can take one step, you can take another. If you can take that one, you can take the next. Do it enough times, and Brittney will tell you when to rest. Artificially intelligent chrono, that's why you got ‘er ... Sentient chrono, gonna send us to the chronister. Chronister? ... Canister. CAN-IS-TER ... Canister, clamister. Caterpillar ... Gonna crawl to the caterpillar. One foot after another. Lots of f
eet; just put one after the other.

  I must have said some of that aloud.

  "Whoa! Stop!” The voice seemed to be floating between strides, just as I was. I looked at the chrono, but it was just being a chrono.

  "Stop, stop! You're babbling. And weaving. Take a break, now!"

  "'Kay,” I said, and tried to sit down. But it was too much effort, so I just kind of flopped over and let the gravity drop me to the ground. The simple act of not running was making the brown haze spin above me. Or maybe it had been spinning all along and I'd not noticed. I closed my eyes, but the spinning continued. One more step; but I was lying down, not walking, and nothing happened.

  So this really is it, I thought, though there was nothing falling on me. Instead, it felt as though I was the one who was falling, upward, into the spiral.

  There was something important I wanted to do, while I could. Something about caterpillars and chronometers, something I could do even if I couldn't take another step. But I was having trouble thinking. I opened my eyes, but it wasn't out there. Then, through the spiraling, it came to me.

  "I don't know why I got you,” I said, fighting to keep my speech from slurring. Then in a moment of clarity—one of those things I'd heard sometimes precedes death—the answer flitted before me. Something about a companion who couldn't die on me, though I guess I had to amend that to unless I did. There was more to it than that, but the moment passed before I could fully grasp the rest. “But I never regretted it,” I said. Except for bringing you here, I tried to add. But it was too late; the spiral had claimed me.

  * * * *

  I woke to an explosion in my spacesuit. No, that wasn't right; the explosion was in my head.

  I'd been dreaming of my mother. “Rise and shi-ine,” she was saying, sounding way too much like Brittney at her perkiest. “Come back, Floyd. Pleeaaase come back.... “Then, while I was trying to figure out whether she was calling me to the Great Beyond or imploring me not to go, my head went pop.

  For a spacer, there's nothing scarier than sudden noises. My mind felt like treacle, but even before I managed to open my eyes, I was listening for the rush of air. At least I didn't have to ask where I was, though I guess the orange-brown sky was a pretty good hint.