Eternal Light

by Paul J McAuley

  ‘We’re stealing this ship, remember? So we can’t go to Earth. You crazy?’

  ‘Yeah. That’s why I put Machine in my head.’

  ‘Maybe Mars,’ Suzy said.

  But she knew that she wanted something for herself, wanted to get out to that fast star, bring back whatever she could find and blow it through the Federation’s circuits. See how the Golden, who wanted everything to stay the same, or to change slow enough to suit them, see how they liked that. And maybe make a pile of money, too; she remembered what the fat simulacrum had said about the incalculable value of ancient alien technologies. Call it revenge. For Shelley, for herself.

  The spacefield’s gravithic generators had been shut down after Robot had blown the rigged ship halfway across Titan’s sky, so the only way to get off this rock was by using chemical boosters inside Urbis’s city limits. But since Suzy was about to commit the capital crime of piracy, she wasn’t about to break into a sweat about violating city ordinances.

  She was lying flat on her back in the wraparound gimbal couch, still in her sealed pressure-suit. She’d flooded the singleship’s lifesystem with impact gel, as much to protect Robot, who was braced in the narrow sleeping niche, as herself. The ship was beginning to shake with building thrust. The roar of its boosters filled the cabin, more physical force than sound…and only a thousandth of the noise it was really making, back of her tail. At least it drowned out the squawking of the spacefield administration tower.

  Vibration sent weird pressure patterns racing through the faintly blue gel pressing against her visor, but Suzy was only vaguely aware of them. Her senses were flayed open, merged with the ship’s systems. She felt thrust building as if she was lifting her own mass on her fingertips, saw in crystal clear three-hundred-sixty-degree vision great plumes of vapour flapping across the crowded grey sails of bafflesquares and fluxbarriers. The panorama was overlaid with the fine print of the myriad readouts of the ship’s systems, any one of which zoomed into legibility if she turned her attention to it. She’d turned the ship’s computer off, in case the field’s tower managed to override it somehow. She was flying by wire, the way she had in the cusp of combat, the vital couple of minutes when her singleship’s orbit had intersected with that of an Enemy habitat.

  Floating right in the centre of her vision was the thrust readout. It was creeping towards equilibrium, the point where the ship’s mass was balanced on the compressed superheated steam of its booster’s hydrox fuel…wavering on the line…there!

  Suzy kicked in the ship’s reaction motor. White hot fire seared away the fog. For a clear moment she saw baffle-squares fly away in every direction. And then the ship was rising, rising smoothly and achingly slowly, boosters almost exhausted now, only scant minutes left to them as the ship rose, restraining pins flying away, methane in the freezing atmosphere smelted into carbon and superheated steam by its fire, a dense black fog boiling up as the ship rose higher, higher than the knife-edge peaks of Tallman Scarp, Urbis a glittering toy draped across them, ice volcanoes distinct cones printed at the horizon line…And then the horizon tilted away and there was only clear pink sky as the ship burned in its slanting trajectory, airbreathers cutting in as soon as velocity passed the critical point, ramming a tonne of methane a second and flaming it out behind, a burning spear aimed at Saturn’s serene ringed disc.

  Suzy was too busy watching flickering blocks of numbers and icons to notice the view. Acceleration pressed her deep into the couch, a wrinkle in her suit cutting into her left buttock, gonna be a hell of a bruise, gel stiffening around her arms and legs, vibration grinding deep into the marrow of her bones. Fracture patterns ran like blue lightning through the impact gel. She had time to notice a fluffy cloud deck below her, red-brown colour of dried blood, and then the airbreathers cut out. Titan’s smog too thin now. The whole ship shuddered, like a salmon making its final leap, and the reaction motor and the exhausted boosters cut off. They’d made orbit.

  ‘Jesus Christ,’ Robot’s voice said weakly.

  Suzy asked if he was all right, tuned down his chatter after he said that he was. There was a really strange signal coming up over the horizon, maybe twenty thousand klicks out and going past like a stone dropped from infinity, radar dense objects fleeing a fuzzy expanding centre, their trajectories defining a parabolic curve: all headed towards Saturn.

  Sure.

  Suzy set the ship’s optical system to track at maximum magnification, and was rewarded with a view of all kinds of debris expanding away from riddled slabs of, what? Laser spectrography told her there was olivine and diopsite, asteroid stuff, mixed with a variety of alloys…She looked away from the lengthening list and it shrank back to a point. Fragments twinkled as they tumbled in raw sunlight—were those trees? Yes, broken pine trees spinning away amongst all the junk.

  Backing down magnification, Suzy tracked half a dozen exhaust trails on infra-red, radiator fins of the reaction motors of intrasystem cargo tugs according to the identification key: if the computer had been locked in, it could have maybe told her who the tugs belonged to, but instinctive caution clamped down on the impulse. Hard to say what had happened, but she was sure that the debris was what was left of Barlstilkin’s ship.

  Suzy smiled inside her helmet. Tricky son-of-a-bitch, he’d be on one of the tugs all right, but they were all aiming for slingshot encounters with Saturn. In less than a day they’d be spread across half the sky, vanishing in radically different directions. Follow that! Her gut reaction was confirmed a moment later when she spotted the neat formation of three singleships vectoring down on the wreckage. RUN cops without a doubt. Then the tableau set below the horizon of Titan, and she turned her attention back to her own orbit.

  And saw the singleship dawning over Titan’s muddy limb, right on her tail. She kicked in the reaction motor, and its flare burned across the ashen light that sullenly limned the nightside.

  Robot was demanding to know what was going on, and Suzy told him that a ship had come up after them, they were moving into a higher orbit, easier to break out when the time came.

  ‘Hey, but where are we going? Won’t he be able to catch us?’

  ‘There’s maybe one place he won’t follow us. You’re not gonna like this, Robot, but there’s no way we can even get close to Mars with him on our tail. Now pipe down, I’ve some figuring to do.’

  Which wasn’t really true, because she wouldn’t be able to figure the fine vectors until she got there. For now, it would be strictly line of sight navigation, aiming at the biggest target in the sky. But she wanted time to think, and she didn’t want to argue with her passenger. Let him figure out what was happening, by then it would be too late for him to do anything. She hoped.

  The tailing ship had matched her new orbit, Suzy noted, no real surprise. Adrenalin was thrilling in her blood. The real thing, the true high. Kite flying no substitute. They were coming round towards Titan’s dayside now, the shrunken point of the Sun dawning a few minutes before Saturn himself rose, a winged half-sphere almost as big as the turning globe beneath her.

  Soon be back over Tallman Scarp, Suzy figured. Well, hell, aim and point, right? She fired up the reaction motor again, acceleration pushing her back into the couch with slightly more than Earth’s grip. Her pursuer was hidden by the glare of the reaction motor’s photon wake, but she knew that he would be accelerating too.

  Out of Titan, bound for Saturn.

  Think of two fixed points either side of an ocean, on a planet so huge that surface curvature is negligible. Obviously, the shortest distance between them is a straight line. Now fling one point away at a thousand kilometres per second, so it describes an orbit, an ellipse, around the first; and for good measure have both points fly off in some arbitrary direction, the first revolving around the second, both revolving around a common centre. Now it’s not only a question of distance, but of velocity, of time. In space, the shortest path between two bodies is always a hyperbolic curve.

  ‘See, if we aimed st
raight at Saturn, we’d miss because we still have Titan’s orbital velocity. So really, we’re slowing down relative to Titan, ’cause we’re going in the opposite direction.’

  ‘Even though we’re going faster all the time.’

  ‘We’re accelerating to slow down. We were travelling even before we left Titan. Titan is moving around Saturn at a particular orbital velocity. Well, see, that’s what we’re shedding, to get into a lower orbit.’

  ‘I don’t know,’ Robot said, for maybe the fifth time. ‘It all sounds like some koan to me.’

  ‘So sit back and enjoy the view.’ They’d been batting the concept of intrasystem navigation around for more than an hour now, and Suzy was more than a little tired of it. She’d set up an internal link between Robot’s implants and the ship’s optical system, so at least he could see what was going on around them. But was he satisfied?

  Now he asked, ‘What about the cop?’

  ‘I guess he’s still there. But I’d have to switch off the drive to see him, and I’m not about to do that.’

  ‘So he could be catching up. Or he could fire something at us, a missile maybe.’

  ‘A missile couldn’t match our acceleration for long. Anyhow, it would burn up in our exhaust. No, thing I’d do if I was him would be hang in there, wait until Saturn’s pull begins to make a difference. Then ease off and overshoot, turn the ship, let the exhaust cut us in half. Think of a reaction motor as a really big laser.’

  ‘So while we’re falling like a stone from an infinite height,’—which was how she’d first tried to explain the transfer orbit to him—‘we could get sliced in two by a thousand-kilometre-long plasma jet.’

  ‘Photons. I’ve seen plasma weapons. Believe me, they’re a lot worse.’ Down in the gravity well of BD Twenty, this tremendous hot glare coming at you at a fraction under the speed of light, naked quantum particles boiling away your hull in an instant. Ffffp! Ant under a lens. Suzy said, ‘Keep quiet a while, I’ve got to fine-tune vectors.’

  ‘What you’re planning is illegal as all get-out, isn’t it? I mean, it’s a protected astronomical—’

  ‘Think of it this way. You’re going somewhere no one else has been for more than five hundred years. Now I really got to do some figuring.’

  ‘Aye-aye, Captain,’ Robot said.

  Suzy chipped into her player and selected a random couple of hours’ worth of twentieth-century blues, then got down to the business of working through the encounter. The sooner she could make the final, delicate changes in the ship’s hyperbolic trajectory, the easier it would be. But there was so much stuff down there…

  Hours slid by; Suzy hardly noticed as she ordered and reordered matrices, sliding them through a hundred different solutions to the problem. All had to have the same outcome: the summation of deflections of the singleship’s course should give it the velocity, and more importantly, the relative proper motion, to match its next target, the neutron star whose absolute position, like all the rest of the crazy mission profile, had been burned into her by hypaedia. For momentum is conserved during translation through contraspace, and just as planets and moons sweep out orbits, so do stars.

  Saturn grew beyond the grids of Suzy’s calculations, but she had eyes only for a single bright point near the Cassini Divide which halved the lanes of the rings. Everything but that point and the sliding calculations receded to the periphery of her horizon: the lonesome voice of some wailing Louisiana bluesman; the continual rumble of the reaction motor; the fug of sweat and rebreathed air in her suit; the tug of the suit’s relief junction; the cradle of couch and impact gel; the itch of her bruised hip.

  Music and mathematics flowed through her, a pure oceanic feeling. Fucking three-body problem, just the kind of thing she’d sweated over in the Academy. Boltzmann derivations hairy with four space integers, little knots of figures like black holes in her consciousness. But she had to admit she’d missed this stuff.

  Her passenger was, thank Christ, quiet. Thing he’d said back before she’d taken the ship up, when he’d been curing his sabotage. But for your tattoo, Seyoura, Robot might not have come, but we admire the impulse behind it. Es muy simpatico. Thought it matched his own mutilations, maybe. Doing that to your brain. Christ. Stone-Age stuff, like trepanning. Except he was letting evil spirits in. Still, maybe handy for maths. There were times when she was almost tempted to turn on the computer, risk being overridden by the cop on her tail.

  And so time passed until, the rings huge and close now, showing grainy structure within their shining lanes, the ship’s s&v system flared with whiteout and a hideous siren. Music and ringscape vanished. Suzy turned everything down, cut in auxiliary channels so she could see and hear again: but she couldn’t turn off the voice that was suddenly on every channel.

  ‘You are approaching the boundary of the Saturn Astronomical Conservation Area,’ the voice said. It was a woman’s voice, sibilant and sweet, speaking a pure unaccented Portuguese. ‘Please adjust your orbital trajectory at once. Trespass within five thousand kilometres of the mean orbital path of the ring system is strictly forbidden.’

  Robot said over it, ‘This is the cop?’ His voice pitched high with fright.

  ‘Hell no. Just a warning buoy. And how did you tap into this channel anyhow? I thought I’d turned you off.’

  ‘Your ship has been identified as Intersystem Singleship MV 397E222894. Please be advised that a record of your course is being recorded and transmitted to Urbis Traffic Control, Titan. Trespass within the proscribed boundary of the Saturn Astronomical Conservation Area will result in subsequent confiscation of your ship. This announcement constitutes sufficient due warning under RUN Human Rights Charter 2698.’

  ‘Robot is not bound by machinery. Robot uses machinery.’

  ‘You are approaching the boundary of the Saturn Astronomical Conservation Area…’

  And then the voice faded to a whisper. ‘There,’ Robot said, sounding insufferably smug. ‘No laws, right?’

  Suzy chipped into the ship’s internal s&v for the first time since they’d lifted off from Titan, a bright little bluetinged window hung before Saturn’s rings. Robot was crammed inside the sleeping niche, all right, strapped up inside a crash cocoon as snug as a bug: but he was surrounded by a kind of web of cables and wires and jacks that snaked through the impact gel and mostly disappeared behind a padded panel pulled out from the wall. His little rat-machine sat amongst the web in a kind of bubble in the impact gel, limbs folded like a dead spider.

  Somehow, Robot had managed to subvert the buoy’s broadcast. Which was, theoretically, impossible. Still, he hadn’t managed to cut it off altogether, which meant that there were limits to his powers. But it was too late to worry about him. At long last, it was time to make a move of her own.

  Suzy accessed the ship’s library, cued the selection she’d been saving for this moment. Something with real kick to it.

  The first notes of the guitar bent in; then the voice, hectic and hoarsely mannered, in an accent lost to history.

  I got to keep movin’, I got to keep movin’

  Blues falling down like hail…

  Yeah, it was the story of her life. And here she was, hung on the very edge. Let’s see the cop follow this.

  The rings filled her vision now, the Cassini Divide an aching vacuum between. She called up a cursor to bracket the fleck of light that was her target.

  ‘You fly a funny ship,’ Robot said in her ear.

  ‘You don’t like it, where we’re heading there’s plenty of rock to sit and wait for another ride.’

  And the days keeps on worryin’ me

  There’s a hellhound on my trail

  ‘Robert Johnson,’ Robot said. ‘Real gone blues. Check that I know my history. We access a gigabit memory, Seyoura. Robot offers it to you, should you need it.’

  ‘Christ, and you think I’m strange. Now keep quiet, huh? Enjoy the ride. We’re coming up to a little course correction, and I want to see if that cop can walk
the edge…’

  Her bracketed target was growing closer, right at the edge of the rings’ braided rivers of billions of nuggets of ice and rock and primeval carbon left over from the solar system’s condensation, too close to Saturn’s bulk ever to collapse into a proper moon. But there was order in the apparent chaos. Small shepherd moons rode shotgun on the two dozen sub-divisions of the rings, each balancing the teeming orbits of a million nuggets against Saturn’s pull. Suzy had bracketed one of them, a ten-million-tonne flying mountain. The singleship was accelerating straight for it.

  ‘…is strictly forbidden. Your ship has been identified…’

  The rings were like a solid plane beneath her now, a shining tilted surface skimming past. She feathered the ship’s attitude, a final adjustment, risked breaking her concentration by looking back, but saw no sign of the cop. Hanging right in there, in the glare of the reaction motor. Well, now she’d test his fucking nerve to the limit.

  ‘Oh man,’ Robot said, ‘we are truly in the groove.’

  ‘Keep quiet, for Christ’s sake.’

  It keep me with ramblin’ mind, rider

  Every old place I go

  Seconds now. They were plunging at an acute angle towards the seemingly hairline crack that divided one lane of debris from the next.

  ‘Please adjust your orbital trajectory at once. Trespass within five thousand kilometres of the mean orbital path of the ring system…’

  ‘I am going to fucking adjust it,’ Suzy muttered.

  ‘Man, this is just crazy…’

  ‘Quiet!’

  Proximity warnings lighting up all over Suzy’s wraparound vision, strays above the ring plane. Thin seething impact of dust on the hull, molecule-sized grains scattered one to every cubic centimetre. It hissed through the singer’s wailing voice. Suzy could see the structure of the rings now, grainy and three-dimensional, and then the timer closed on zero and she cut the motor, praying that the cop had chickened out because this was his chance to overtake and blow them out of the sky. Robot said something she didn’t catch because she was too intent on the churning edge of the ring; actually glimpsed the tumbling cratered target…