The Long Mars

by Pratchett, Terry; Baxter, Stephen

  Just do your job, airman.

  As it happened they came across traces of another near-miss civilization the very next day, only fifty thousand worlds plus change past the meaningless million-step milestone.

  The crater was a few tens of miles south of Mangala itself, the glitter of metal easily visible from the air, and spotted by their image-processing software as they stepped through.

  This time Frank was piloting Willis as the gliders flew over. The crater was a great bowl in the ground, deep and clear-cut, maybe a half-mile across. But its inner surface gleamed with some kind of metallic coating. From a height, Frank could see that the bowl itself was littered with inert objects, crumpled and fallen: machinery of some kind, perhaps. And some parts of the crater, and the land near by, were blotted black, as if bombed from the air by immense bags of soot. The crater appeared to be joined to a wider landscape by straight-line trails of some kind, but they were old, faint, dust-choked.

  Willis growled, ‘Another close call, dammit. Another still-warm corpse. I see no movement, am picking up no signals. You want to take us down, Frank? Sally, station-keep.’

  ‘Yes, Dad,’ came a dry reply. Sally tolerated being ordered around by her father in situations like this, but just barely.

  Frank dipped the glider’s nose. As they skated in towards the bowl of the crater, Frank noticed that swathes of the surrounding terrain were glassy, glinting in the weak sunlight as the land flowed by under the glider’s prow. He remarked on this to Willis.

  ‘Yeah,’ Willis replied. ‘And look in the crater.’

  As they skimmed over the bowl one more time, Frank saw that the crater’s inner surface appeared to have been coated with sheets of some kind of metal, but the lining was extensively damaged, torn away by explosions – and melted, in part. ‘Radiation weapons? Lasers?’

  ‘Something like that. I think this may have been some kind of telescope – like Arecibo, rigged up in the natural bowl of the crater. If the surface was mirror-like, maybe it was optical. You’d get a great view of Earth with a thing like that, given its location.’

  They flew deeper into the bowl itself now. Frank was wary of any surviving superstructure, but he saw nothing: the destruction had been comprehensive. Piled up in the bowl’s depths was a tangle of smashed equipment, much of it of elaborately sculpted metal. At first he could discern no signs of life, no biology down there. But then he made out shards of chitin that looked vaguely familiar.

  ‘Put us down,’ Willis said. ‘We may as well take a few samples. Sally, stay aloft . . .’

  They came down a short distance from the mirrored pit, and walked over.

  When they clambered down into the pit itself, clumsy in their pressure suits, the deep cold seemed to intensify. At the bottom, there was no sign of recent activity; a layer of windblown dust seemed undisturbed. Willis snipped a few samples of metal components, the reflective surface, the chitin-like remains.

  Frank said, ‘This shell stuff looks familiar. Like traces of the crustaceans we’ve been seeing from the beginning.’

  ‘So it does. There is a certain consistency, isn’t there? I’m thinking of what we’ve seen: the crustaceans, the whales. A kind of common palette; maybe we’re going to find distorted versions of those families wherever we go, differently evolved.

  ‘I think I see how it would work . . . You have a rapid evolution of life forms, species, families, genera, while Mars is young. Pretty much identical on every world of the Long Mars. But then a given Mars shrivels, and whatever survives has to hibernate, aestivate. Mostly Mars stays dead, but on Jokers like this the root stock takes its chances when they come, adapting in different ways depending on the details of the environment. An endless reshaping of the same primordial stock – variations on the theme of whales and crustaceans, and maybe other sorts we’ve yet to identify.’ As he spoke Willis kept working, patiently studying the melancholy debris. ‘I’ll run this through the assay gear on the glider.’

  ‘I take it the tech artefacts you’re looking for aren’t here.’

  ‘No. Disappointingly. Though this is the highest culture technologically we’ve encountered.’

  ‘You’ll know it when you see it, will you, whatever it is?’

  ‘You can bet on it.’

  ‘How do you even know this thing exists?’

  Willis didn’t look up from his work. ‘This is Mars. On such a world it’s a logical necessity.’

  Frank knew that they were all getting on each other’s nerves anyhow, but this deliberate obscurity of Willis’s increasingly niggled him. What was he, a chauffeur who couldn’t be trusted with the truth? ‘Secrecy and certainty, huh? Those traits have helped your career, have they?’

  Willis just ignored him, which annoyed him even more.

  ‘Sally compared you to Daedalus. I looked him up. In some versions of the story he invented the labyrinth on Crete, where they kept the Minotaur. Problem was, he didn’t think through the consequences. Made the labyrinth so intricate it was hard to pin down the beast if you needed to slay it. Not only that, it had a design flaw. With a simple ball of thread you could make a trail to find your way out – Daedalus never thought of that.’

  ‘Is this storytelling going anywhere, Wood?’

  ‘Maybe you are more like Daedalus than you think. What will you do with this bit of Martian tech, if you find it? Just unleash it on the world, like the Stepper box? You know, you and Sally, father and daughter, you both treat mankind like it’s some unruly kid. Sally slaps us around the back of the head when she thinks we’re misbehaving. And you, your way of teaching us responsibility is to hand us a loaded gun and let us learn by trial and error.’

  Willis thought that over. ‘You’re just sore because you’re an old space cadet. Right? Step Day stopped you from getting to fly around in the space station measuring the thickness of your piss in zero gravity, or whatever those guys did up there for all those years. Well, bad luck for you. And whatever we do, at least we have mankind’s best interests at heart. Me and Sally, I mean. Now. Does this conversation have any point, Frank?’

  Frank sighed. ‘Just trying to figure you two out.’ He looked down at the silent war zone. ‘God knows there isn’t much else to do on this trip . . .’

  ‘Ground party, Thor.’

  Frank tapped the control panel on his chest to switch over his comms circuit. ‘Go ahead, Sally.’

  ‘I’m picking up some residual background radiation.’

  Now there was movement, out of the corner of Frank’s eye. A vent of some greenish smoke, puffing into the air from a pile of dust-coated debris.

  Sally said, ‘The builders and warriors are long dead, but maybe the junk they left behind isn’t. Suggest you get out of there.’

  ‘Copy that. Come on, Willis.’

  Willis followed without arguing as Frank clambered out of the pit. Frank glanced up at Sally, flying high in the air, a Martian Icarus. Then he looked away, concentrating on where he put his booted feet on the uneven slope.

  27

  EVERYBODY ON MAGGIE’S airship thought they’d have to get out of the ‘Anaerobic Belt’ before they came across complex life once more. As it turned out, everybody was wrong, and not for the first time.

  Earth West 161,753,428: ten days after they’d entered this thick band of oxygen-free worlds, the twains drifted over a landscape teeming with life, big, complicated, active life. Evidently this was a new complexity band – but, this deep into the stepwise worlds, the life forms they saw below were very different from anything they’d encountered before.

  Maggie was standing in the observation gallery with some of her senior crew. These included Mac and Snowy the beagle, at her insistence, in the vague hope that forcing the two of them into the same space might bring to a head whatever issue was bubbling between them. Not yet it hadn’t. And, as it happened, Captain Ed Cutler was here too; he’d come over for his weekly face-to-face with Maggie.

  The ships, side by side, were drifting throug
h a yellowish sky laced with very odd-looking clouds, over a greenish sea, that lapped against a shore of pale brown streaked with scarlet, purple. The very colour scheme was distracting, as though it had come out of some doped-up college student’s imagination. On the land were banks of what had to be vegetation, including what looked to Maggie like ‘trees’, tall structures with trunks and some kind of leaf-like arrangement on the top, evidently a universal formation wherever you needed light from the sky but had to be rooted to the ground for nutrients. But those ‘leaves’ were crimson, not green. Gerry Hemingway had told her they were busily photosynthesizing, leveraging the sun’s energy – but unlike Datum trees, what they seemed to be absorbing from the air was not carbon dioxide but carbon monoxide, and what they were producing was not sweet oxygen but hydrogen sulphide and other unpleasant compounds. Around the clumps of ‘forest’, meanwhile, stretched swathes of some kind of ‘prairie’ of more diverse vegetation, but nobody knew what the hell grew there yet.

  And, among the vegetation, animals moved. Nothing like Datum animals. Maggie made out a disc, translucent, huge, like a cross between a jellyfish and a Hollywood UFO, that slithered and slurped and morphed its way over the land. No, not just one disc: a whole family, a herd maybe, big adults with little ones skittering alongside. Gerry Hemingway wondered if they moved by some kind of ground effect, like an airship.

  It didn’t aid comprehension that all this was played out at a manic speed, as if the world outside was stuck on fast-forward. Hemingway’s biologists suggested that was something to do with the higher temperatures of this world, an increase in available energy. Still, whatever the justification, Maggie wished all this shit would just slow down. And—

  ‘Mao’s eyebrows!’ That, astonishingly, was Lieutenant Wu Yue-Sai. She turned to Maggie and blushed. ‘I must apologize, Captain.’

  ‘The hell you must. What do you see?’

  Wu pointed. ‘There. No, there! In the trees – it is long, muscular, like a snake. A huge one. But—’

  But this ‘snake’ hurled itself through the air, from tree to tree. No, it did more than that, Maggie saw; it was streamlined, kind of like a flexible helicopter blade, and it was wriggling as it moved through the air. It was purposefully gliding – even flying, if you wanted to stretch a point.

  Gerry Hemingway whistled. ‘A twelve-foot-long flying snake. Now I’ve seen everything. No, wait – not yet I haven’t.’

  For the ‘snake’ had hurled itself on one of the disc creatures, a little one, an outlier. There was a hiss of steam, the disc wriggled and thrashed, but Maggie saw the snake sink inside the disc, and once within, it began to twist and tear its way back out again.

  ‘Eating its victim from the inside out,’ Mac said. ‘Having burned its way in with some kind of acidic secretion. Charming. Everywhere you go, herbivores and carnivores, the dance of predator and prey.’

  Maggie forced a laugh, to try to lighten the mood. ‘Maybe, but I bet you never thought you’d see it quite like this, did you?’

  Cutler was standing rather stiffly beside Maggie. He never was one for social occasions. He said now, ‘I suppose we need to find somewhere rather more isolated for a safe landing for our shore parties, Captain? The crews could use some R&R; we’ve been cooped up a long time . . .’

  The group fell silent at this. Maggie felt embarrassed for the man.

  Mac had no such compunctions, however. ‘Captain, are you suggesting we actually send crew down there?’

  ‘I don’t see why not. We’ve landed on exotic Earths before.’

  ‘Sir, do you ever pay attention to the science briefings from your officers?’

  Maggie murmured warningly, ‘Mac . . .’

  ‘Not if I can help it,’ Cutler said defiantly.

  Mac looked around. ‘Gerry, do you have what’s left of that first drone we sent out, so we can show it to the Captain here? The damage to its hull – no? . . . Never mind, I’ve a better idea.’ He made his way to the wall of the observation gallery, where a series of lock-boxes had been fixed to allow the collection of atmospheric samples. He donned a protective glove, reached inside and pulled out a flask of gas, yellowish in the deck’s fluorescent lights. ‘The air,’ he said, ‘of Earth West 160,000,000 plus change. And do you know what we found in here, Captain?’

  ‘No free oxygen, I know that much. Water vapour?’

  ‘Good guess. But not just water. Highly acidic water. Captain Cutler, that’s the story of this world. The oceans are more like dilute sulphuric acid. So are the rivers. So’s the rain. And so is the blood of these creatures down below, the couple we managed to snag with drones. Why, you just saw it in action, as that snake thing must have concentrated its bodily fluids to burn its way into that protoplasmic beast—’

  ‘Ed,’ Maggie said quickly, hoping to defuse the situation, ‘the science boys think that on this world, in this band of worlds, water, I mean neutrally acidic water, isn’t what life uses as – what’s the term, Gerry?’

  ‘A solvent. Which means, in this context, something to provide a liquid environment within which the chemistry of life can happen. On Datum Earth, we use water. Here—’

  Cutler asked, ‘Acid?’

  ‘That’s the idea,’ Mac said. ‘There’s a whole biosphere based on that simple fact, that difference. But we’ve barely started to scratch the surface.’

  Hemingway said, ‘We have here a suite of life that’s made up of the same basic molecules as us, Captain Cutler, but with an entirely different chemical basis. Perhaps the plants absorb carbon monoxide and secrete hydrogen sulphide. In any event it would be extremely hazardous, to say the least, for a human to venture down there without very heavy protection.’

  Maggie said, ‘But the ships are sound. The hull, the envelopes can withstand the dilute acidity of the rain. Obviously we’re keeping our internal air supply sealed off. I’m sure you’d have been briefed by your XO if she’d perceived any problems, Ed.’

  Cutler was quite unperturbed, Maggie saw. He was a man whose mind was thoroughly compartmentalized, and he liked it that way. The nature of these exotic worlds, unless his ship was directly endangered, was something he didn’t need to hear about, and he’d no doubt instructed his crew in that regard. Still, he seemed to show a flicker of curiosity as he asked now, ‘So what went wrong?’

  Hemingway stared at him. ‘Pardon me, sir?’

  ‘I mean, how did these worlds get this way, instead of producing regular oxygen-breather types like us?’

  Hemingway said cautiously, ‘Well, we can only guess, sir. We’ve only spent a couple of days with a whole new kind of biosphere.’

  Maggie smiled. ‘Guess away, Gerry, you’re all we’ve got.’

  ‘We think that these worlds, for whatever cause, must have gone through a phase of extreme heat when they were younger. Maybe they were like Venus, for a time, with thick atmospheres, ferocious heat at the surface. The thing about Venus, though, is that we’ve always suspected life was possible up in the clouds, where it’s cool enough for life, if you pick the right altitude. There could be some kind of bug tapping solar ultraviolet, and using whatever chemical resources it can find to live on up there. Notably droplets of sulphuric acid – because the acid, you see, has a higher boiling point than water, and is available as a solvent where liquid water isn’t . . . The point is, maybe this Earth was like Venus, our Venus, when it was young.’

  ‘OK. But this world isn’t like Venus now.’

  ‘No, sir. But maybe it – recovered. Cooled down again, rather than suffer the full catastrophic heating of our Venus. It became more – well, Earthlike. But that acid-based life, once it got a foothold, stayed in control. And the result is the acid biosphere you see below.’

  ‘Hmm. Sounds kind of pat to me. And I— What the— Back!’ To Maggie’s blank astonishment, Cutler pulled his handgun, crouched down, and pointed it two-handed at the hull wall.

  Then she turned and saw the snake.

  It came twisting and turnin
g, riding the yellowish air – yes, it was undoubtedly flying, purposefully. And it was heading straight for the ship, for this observation gallery, and what must look like fresh meat to a flying, acid-blooded, snake-like predator . . .

  ‘Keep calm,’ snapped Nathan Boss. ‘It can’t do us any harm. The hull, the windows, are resistant to—’

  The beast slammed into the hull, its whole body sprawled across the window. Maggie got a nightmarish glimpse of the animal’s underside, an array of suckers and ribbed flesh and things like tiny lips that mouthed the window surface. She even saw some kind of liquid come squirting out, fizzing. She remembered the fate of the jellyfish down on the ground, and her skin crawled at the imagined touch of acid.

  And Ed Cutler ran for the wall, towards the snake, gun in hand. ‘I got this,’ he said.

  Maggie grabbed for him, missed. ‘Ed! No! Let that thing off in here and you’ll either crack the hull and kill us all, or the ricochets—’

  ‘I’m not a fool, Captain.’ He jammed the weapon into one of the air-sample lock-boxes. ‘These things will self-seal, right? Same design on the Cernan. Eat this, acid boy.’

  And he fired the gun. The noise was enormous in the enclosed space. Maggie saw the projectile pass through the snake’s body and splash away into the air, leaving a ragged hole. The animal thrashed and squalled, and lost its grip and began to fall away.

  ‘Let me finish him off,’ Cutler said, changing his stance, repositioning the gun.

  ‘For Christ’s sake stop him!’ Maggie yelled.

  Mac was the closest, Snowy the fastest. Between them they hauled Cutler away from the window, and Mac forced the weapon out of his hands.

  Cutler stopped struggling, and they released him. ‘All right, show’s over.’ He was breathing hard, his face flushed; he glowered a look of pure hatred at the beagle, then turned to Maggie. ‘Decisiveness, Captain Kauffman. That’s a quality usually attributed to me, in the face of danger—’