Prefect

by Alastair Reynolds

  "You were quicker than I was expecting," Dreyfus observed. "Any hitches?"

  Sparver stared at his sleeve until it cleaned itself. "Not at all. I got in and out without a snag."

  "What did you find?"

  "Nothing to write home about. A piece of free-floating junk about the same size as the cutter. I grappled in and spacewalked. Took me about two minutes to find the right module and patch in a froptic. After that it was plain sailing." His gently slanted eyes were pink-rimmed, as if he'd been up all night drinking vodka. "Heard from Thalia since I left, Boss?"

  Dreyfus shook his head. "I reckoned she'd work faster without me breathing down her neck every five minutes."

  "She'll get the job done, don't worry about that."

  "I sincerely hope so."

  "You have doubts?"

  "I can't help worrying. She's a good deputy, but she's barely out of school. I know she wants to prove to us all how good she is, but sometimes I think she's overcompensating for what happened to her father."

  "What was your take on that?"

  "I didn't know Jason Ng all that well. But from what I did know, I never had cause to doubt his abilities or his dedication to Panoply."

  "So you were surprised?"

  "We all were."

  "You ever talk to Thalia about it?"

  "The subject's never come up."

  Sparver smiled. "She'd hardly be the one to raise it, would she?"

  "Whatever I might think of her father, it has no bearing on my opinion of Thalia. I wouldn't have selected her for my squad if I'd had doubts." Dreyfus took his cup and sipped at it gently, blowing on the tea to cool it. "Isn't that all the reassurance she needs?"

  "There are still prefects who won't look her in the eye when she goes to the refectory," Sparver said. "I know how that feels."

  "They also resent her because she was promoted to Deputy Field One ahead of most of her classmates."

  "I just sometimes wonder if we truly understand what it's like for her, working for the same organisation that tarred and feathered her father."

  Dreyfus shrugged. He had no real opinion on the matter. Jason Ng had been outwardly competent and trustworthy, but it was a matter of record that he had obstructed an investigation into a mid-rank habitat suspected of voting fraud. He had been found dead, having committed suicide in a cargo airlock. Postmortem audits revealed how Ng had been receiving bribes from parties connected to the habitat. He had killed himself because his culpability was about to be made public, and he wished to spare Thalia the shame of watching her father go through a humiliating tribunal.

  Dreyfus didn't care. He did not believe in an inherited disposition for accepting bribes or perverting investigations. If anything, he believed that Thalia would make a better prefect than many of her peers. She wanted both to redeem her father's sins and show that she was not a slave to her genes.

  "She's a good deputy," he said again. "That's all that matters to me. And I have every confidence that she'll pull this off without our assistance."

  "You didn't sound confident just now."

  "I'm entitled to entertain reasonable qualms. But that's all they are. And face it, Sparv: Thalia chose to bite this one off on her own. She'd hardly welcome the arrival of a back-up squad, even if we could spare the personnel."

  "You're right, as usual. I just have this horrible feeling that we're dancing to someone else's tune, spreading ourselves too thinly. We've got Thalia trying to seal the Perigal security hole; we've got you and me trying to nail whoever murdered Ruskin-Sartorious; we've got the rest of Panoply trying to keep the habitats and the Ultras from cutting each other's throats. Is it me or is this starting to feel like an unusually busy week?"

  "Look on the bright side," Dreyfus said. "Thalia's going to be done soon: that'll be one case closed. And we're making solid progress on the Ruskin-Sartorious investigation." He studied Sparver with sudden intensity. "We are, aren't we? Or did you just drop in for tea and sympathy?"

  "Tea. For sympathy I go elsewhere. Mind if I use your wall? I want to show you what I got from the router."

  Dreyfus extended a hand. "Go ahead. It's group-conjurable."

  With the slightly exaggerated patience Dreyfus had sometimes come to recognise in his underlings, Sparver walked him through the data. There were five columns of information: the time of arrival of an incoming transmission, its point of origin (the next node up the line), its intended destination (the next node down the line), the time when it had been forwarded — typically only a few nanoseconds after it had come in — and a final column giving some sketchy information concerning the contents of the transmission.

  "There's a lot of CTC traffic coming through," Sparver said, indicating a proportion of columns with a particular flag in the fifth column. "That we can dispense with. It's just navigational housekeeping data, keeping tabs on all the ships and drones moving through the Band." Sparver removed the CTC data, leaving many blank lines in the wall display. Dreyfus felt cheered: they were getting somewhere. But his glad frame of mind didn't last long. The remaining data shuffled up to fill the gaps, leaving the wall looking much as it had before. He reminded himself that he was only seeing a small, illustrative portion of the entire router log, and that there were millions of lines above and below the visible segment.

  "Now we do a similar filtering on polling traffic," Sparver said. "That takes care of another major chunk of the data. Run the same trick on traffic on the major trade nets and we delete another big chunk. It may not look like an improvement, but we've already shrunk the log by about half. But we can do better still. Clear out all router housekeeping and we drop another ten per cent. Clear out standard abstraction packets and we're down to about twenty per cent of our original file."

  It must still have been tens of thousands of lines. "We'll need to do better than that, even," Dreyfus said.

  "And we can. Now we filter on the target address of Ruskin-Sartorious." Sparver scrolled up and down to show that he had now reduced the log to a mere thousand lines or so.

  Dreyfus scratched at his left eyebrow. "Why didn't we just jump to this point in the first place?"

  "Doesn't work like that," Sparver said. "Like almost every habitat in the Glitter Band, Ruskin-Sartorious would have handled onward forwarding of third-party data, including CTC services, trade talk, abstraction packets, the works. We'd still have had to strip all that from the list even if we narrowed it down to messages only going to Ruskin-Sartorious."

  "Would have been faster, though."

  "But logically equivalent. The system doesn't care in which order you do the filtering."

  "I'll take your word for it. But we're still looking at a mass of data."

  "We're not done. Now we start getting clever."

  "I thought we were already being clever."

  "Not enough." Sparver smiled — he was clearly enjoying himself. "See that number in the fourth column?"

  "Yes," Dreyfus said guardedly. "Timetag for outgoing transmission."

  "That's our clue. The message that came through to Ruskin-Sartorious was voice-only, right?"

  "According to Vernon and Delphine. What difference does the message format make?"

  Sparver drank from his cup. "It makes a world of difference. When a transmission goes through the router, it's subjected to a certain amount of routine processing. Cyclic redundancy error-checking, that kind of thing. If there's a fault, the router sends a message back to the previous sender, asking for a repeat transmission."

  Dreyfus nodded provisionally. "Makes sense."

  "The point is, all that error-checking takes a finite amount of time. And the heavier the data burden — the more content there is in the message — the more number-crunching needs to be done."

  "Ah. I think I see where you're going."

  "The key's in the outgoing timetag, Boss. Compared to most of the traffic the router would have forwarded to Ruskin-Sartorious, voice-only comms are hardly worth mentioning. The processing delay would h
ave been almost zero."

  "So when the time difference between the incoming and outgoing tags is smallest — "

  "We'll probably have isolated our message. Or at least some possible candidates."

  "Do it," Dreyfus said excitedly.

  Sparver was ahead of him. Now the wall showed only a dozen transmissions, all falling within the likely interval when Delphine had been warned to break off negotiations with the Ultras.

  "We're still not down to one — " Dreyfus began.

  "But we're getting damned warm. Now we can apply some good old intuitive police work. We look at the originating nodes. Check out the second column, Boss — I've resolved the addresses into recognisable names. Now, I'm willing to bet that most of them will correspond to habitats that have either been in contact with Ruskin-Sartorious over a long period of time, or which are places we'd expect to broadcast to the entire Glitter Band on a fairly regular basis."

  "Can you check that?"

  "Already did. You ready for this?" Sparver sent a command to the wall. Now there was only one transmission entry left. "You'll need to look over the eleven I rejected, but I'm pretty confident we can rule them out. This one, on the other hand, sticks out like the proverbial."

  "In what way?"

  "The point of origin isn't anywhere I recognise, which immediately sets off my alarm bells. It's just a rock, a free-floating chunk of unprocessed asteroid drifting in one of the middle orbits."

  "Someone's got to own it."

  "The claim on the rock goes back to a family or combine called Nerval-Lermontov. Whether that means anything or not, I don't know."

  "Nerval-Lermontov," Dreyfus said, repeating the name slowly. "I know that family name from somewhere."

  "But then you know a lot of families."

  "They could be innocent. Is there any reason to think this rock isn't just another router?"

  "Maybe it is. But here's the odd thing. Whoever made the call, whoever sent that signal from the Nerval-Lermontov rock — whether it originated there, or was just routed through it — that was the only time they ever contacted Ruskin-Sartorious through that particular node."

  "You're right," Dreyfus said approvingly. "Alarm bells. Lots of them."

  Sparver put down his tea, the china clinking delicately against Dreyfus' table. "Never say we pigs don't have our uses."

  * * *

  A flying horse had been waiting for Thalia when she arrived in the Chevelure-Sambuke Hourglass. The animal's wings beat the air with dreamlike slowness, slender legs treading air as if galloping on the spot. Its skin was transparent, affording an anatomically precise view of its tightly packed internal organs, its highly modified skeleton and musculature. The insectile wings were blade-slender, intricately veined, with no visible skeletal underpinnings.

  Thalia's pegasus wasn't the only flying thing in the air. There were other flying horses, visible as slowly flapping translucent forms in the far distance. Some of them had riders; others must have been on their way to pick up passengers or were engaged in some errand of their own. There were also much more colourful things, suggestive of giant patterned moths, striped fish or elaborately tailed Chinese dragon kites. The pegasuses appeared to be confined to the habitat's low-gravity regions (with those prismatic wings it wasn't surprising) but the other flying forms had free roam of the entire interior. Amongst them, almost too small to make out, were the star-shaped forms of flying people, with wings or aerodynamic surfaces of their own. Thalia tried her glasses, but the overlay revealed no significant points of difference compared to naked reality. This confirmed everything that she had read about the Hourglass during her flight: the people here preferred to shape matter, not information.

  Gradually, she became aware of gravity pushing her deeper into the saddle. The horse was aiming itself at a tongue-like landing deck, buttressed out from a spired white mansion near the top of a city constructed on the slopes of the Hourglass's midpoint constriction. As she neared the touchdown point, Thalia observed a civic welcoming party gathered around the perimeter of the deck.

  A pair of functionaries rushed to the side of the pegasus to help Thalia disembark as soon as the horse's hooves clinked against glass flooring. The pull of gravity could still not have been more than a tenth of a gee, but the horse's wings were beating constantly, fanning the air with an audible whoosh on each twisting downbeat. The functionaries — who were more or less baseline human in appearance — moved out of the way once Thalia was on her feet.

  A giant panda-like man, all black and white fur, ambled across to meet her. He moved with remarkable grace despite his obvious mass. His huge head was as wide as a vacuum helmet, his true eyes barely visible in the black ovals of his eyepatches. He stopped munching on a thin greenish stick and passed it to a functionary.

  "Welcome, Deputy Field Prefect Ng," he said in an unctuous tone. "I am Mayor Graskop. It is a pleasure to welcome you to our modest little world. We trust your stay will be both pleasant and productive."

  He offered her his paw in greeting. Thalia's own small hand disappeared into a padding of warm, damp fur. She noticed that Mayor Graskop had five fingers and a thumb, all digits tipped with a shiny black nail.

  "Thank you for sending the horse."

  "Did you like it? We'd have cultured something unique if we'd had more notice of your visit."

  "It was a very nice horse, thank you. You didn't need to go to any more trouble."

  The mayor released his grip. "Our understanding is that you wish to access our polling core."

  "That's correct. What I have to do won't take too long. It's quite straightforward."

  "And afterwards? You'll stay to enjoy some of our hospitality, won't you? It's not often we get a visitor from Panoply."

  "I'd love to, Mayor, but now isn't a good time."

  He tilted his huge monochrome head. "Trouble outside, is there? We'd heard reports, although I confess we don't pay as much attention to such matters as we ought."

  "No," Thalia said diplomatically. "No trouble. Just a schedule I have to stick to."

  "But you will stay, just for a short while." When the mayor spoke, she glimpsed fierce ranks of sharp white teeth and caught the sugary whiff of animal digestive products.

  "I can't. Not really."

  "But you simply must, Prefect." He looked at the other members of the welcoming party, daring Thalia to disappoint them. Their faces, for the most part, were still recognisably human, albeit furred, scaled or otherwise distorted according to some zoological model. Their eyes were disturbingly beautiful, liquid and intense and childlike. "We won't detain you without good reason," the mayor insisted. "We receive so very few outsiders, let alone figures of authority. On such rare occasions that we do, it's our custom to host an impromptu contest, or tournament, and to invite our honoured guest to participate in the judging. We were hoping you'd help with the adjudication in an air-joust — "

  "I'd love to, but — "

  He grinned triumphantly. "Then it's settled. You will stay." He clasped his paws together in anticipation. "Oh, how wonderful. A prefect as judge!"

  "I'm not — "

  "Let's deal with the trifling business of the polling core, shall we? Then we can move on to the main event. It will be a wonderful air-joust! Are you happy to follow me? If you don't like our low gravity, we can arrange a palanquin."

  "I'm doing just fine," Thalia said tersely.

  * * *

  CHAPTER 11

  * * *

  Dreyfus was settled before his console, composing a query for the Search Turbines. He sought priors on the Nerval-Lermontov family, certain that the name meant something but incapable of dredging the relevant information from the event-congested registers of his own ageing memory. Yet he had no sooner launched the request, and was dwelling on the idle possibility of trawling his own mind, when he felt a sudden brief shudder run through the room. It was as if Panoply had suffered an earthquake.

  He lifted his cuff, ready to call his deputy, fea
ring the worst. But he had not even uttered Sparver's name before his console informed him that there had been a major incident in the Turbine hall.

  Dreyfus stepped through his clotheswall and made his way from his room through the warrens of the rock to the non-centrifuge section where the Search Turbines were located. Even before he arrived, he realised that the incident had been grave. Prefects, technicians and machines were rushing past him. By the time he reached the entrance to the free-fall hall, medical crews were bringing out the wounded. Their injuries were shocking.

  A conveyor band drew him into the vastness of the hall. He stared in stupefied amazement at the spectacle. There were no longer four Search Turbines, but three. The endmost cylinder was gone, save for the sleeve-like anchor points where it emerged from the chamber's inner surface. The transparent shrouding had shattered into countless dagger-like shards, many of which were now embedded in the walling. Dreyfus couldn't imagine the outward force that would have been necessary to rupture the armoured sheathing, which was the same kind of glass-like substance they used to form spacecraft hulls. As for the machinery that would have been whirling inside the glass just before it broke loose, nothing remained except a dusty residue, lathered several centimetres thick over every surface and hanging in the air in a choking blue-grey smog. The Turbine — its layered data stacks and whisking retrieval blades — had pulverised itself efficiently, leaving no components larger than a speck of grit. It was designed to do that, Dreyfus reminded himself, so that no information could be recovered by hostile parties in the event of a takeover of Panoply. But it was not meant to self-destruct during the course of normal operations.

  He studied the other Turbines. The sheathing on the nearest of the three, the one that had been closest to the destroyed unit, was riven by several prominent cracks. The apparatus inside was spinning down, decelerating visibly. The other two units were undergoing the same failsafe shutdown, even though their casings appeared intact.