Starfire

by Charles Sheffield

  They shook their heads. "Something about changes to the shield?" Will Davis said. "I've been hoping I misunderstood the message. We can't afford to make changes."

  "I know. Where's Lauren?"

  "On the axis, with the power generation maintenance team."

  "Then we'll start without her. She can catch up later." John waved his hand at Wilmer. "This is Dr. Oldfield. He was on the original Mars expedition. And this young lady—"

  "Young lady be buggered." Astarte finally stood up. She rocked for a moment, then planted her feet. "I'm Star Vjansander, and I'm not a lady. An' if yer don't like me now, wait 'til yer hear what me and Wilmer have ter say. 'Cause yer going ter have ter work yer buns off."

  "That's enough, Star." Wilmer Oldfield turned to John. "I'd not have brought her at all, except that we absolutely can't do without her."

  "Do what without her?"

  "We'll get to that, but it may take a while." Wilmer sighed, subsided into a chair, and rubbed the red patch on the top of his head. "Let me start at the beginning. When we first had the Alpha C blowup . . ."

  Later, John decided that Wilmer Oldfield had a gift for understatement. It may take a while translated into the longest technical briefing ever. Six and a half hours passed before the last question was asked and the last answer given.

  Lauren Stansfield arrived at the end of the first hour, at the point where Wilmer paused for his first break and Star Vjansander began an explanation of the anomalous data from the Sniffers.

  Lauren stared hard at Star but said not a word. She gave John one questioning glance and took her place quietly at Amanda Corrigan's side. Bruno Colombo slipped into the room a few minutes later. He had been hovering uncertainly at the door while Wilmer was speaking. He took a seat next to Lauren. Amazingly, the director also said nothing.

  Finally Wilmer shrugged and said, "That's it, then. Unless you have more questions?"

  John couldn't speak for the others, but he personally felt stunned. Assuming that Wilmer Oldfield and Star Vjansander were right in their analyses, the whole shield project—twenty years of frantic labor—had to be turned on its head. And changes had to be made fast. Instead of years, they had at most months. The only good news was that the proposed changes would make the whole engineering problem easier.

  "Let me make sure I have this right," he said. "Almost all the charged particles won't arrive independently of each other. They will be grouped in stable structures, the things you call bundles, each containing a few trillion nuclei. Instead of building a continuous shield structure, we have to detect each separate group and divert it away from Earth with an electromagnetic pulse generated for just that bundle."

  "Right," Wilmer said, and Star nodded and added, "You got it. All very doable. And the obvious place to put your pulse generator is on Cusp Station, out at the end of the shield."

  "But if your interpretation of the Sniffer data or your supernova model is wrong—if all the particles actually arrive independently of each other—"

  "Then we're up shit creek," Star said cheerfully. "Because the one thing that's for certain is the particle storm is going to hit sooner than you thought six months ago. That means the shield you got now is no damn good no matter what."

  "Suppose you're right," Torrance Harbish said. He had the final word on shield balancing and stability. "All my work for the past eight years will go down the tubes, but that's not what's worrying me. You're saying we have to find and deflect every particle bundle. I don't understand how we'll know where each one is. Remember, they're flying at us at something like ten percent of light speed."

  "We've looked into that." Wilmer did not sound worried. "We generate a wide-angle, low-intensity radiation beam from Cusp Station that extends out toward Alpha C. Easy, and probably best done at microwave frequencies. It won't be anywhere near strong enough to divert a bundle, but each bundle will interact with the field enough to produce its own weak radiation. We can detect that signal when the bundle gets near enough. It will give us enough information to determine the speed and exact trajectory of each bundle. And that's what we hit with a pulse strong enough to divert it safely away from Earth."

  "Do we have time to do all that?" Will Davis, like Torrance Harbish, could see his efforts of many years crumbling to nothing. "It sounds like an awful lot of work. I mean, we have to detect a signal, calculate a trajectory, and generate and fire a pulse. How much time do we have between bundle detection and bundle arrival?"

  Wilmer nodded. "We've studied that, too. Star?"

  "No worries. Yer can't get a useful return beyond about fifteen thousand kilometers. From there the signal takes a twentieth of a second to reach Cusp Station, and the pulse needs that long ter go back. Knock that off the bundle travel time before it gets ter the shield—say half a second—and you're left with point four seconds to generate a pulse and spit it back out ter the bundle. Bags of time. 'Course, it's a monster computing problem to know just where ter fire. But I understand you've got computers up here coming out your wazoo."

  She saw their faces. "Uh-oh. Did I screw up?"

  John spoke first. "I think so. Let me make sure I have this right. We receive a return signal at Cusp Station. From that we compute where the bundle is. On Cusp Station we generate a powerful EM pulse and aim it at the bundle."

  "That's right. Look, we assume you don't have equipment on Cusp Station to generate the signal field or the pulses. That's all right, they can be shipped there easy."

  "Not the problem." Amanda Corrigan was the computer specialist. Shy and gawky, she ducked her head and made her first contribution to the meeting. "You said we had a 'monster' computing problem. How monster?"

  "Yer might need to do simultaneous path computations for a few million bundles a second. I was told you could do that here, dead easy."

  "We can," Amanda said. "Here on Sky City. But we don't have anything near that much power at Cusp Station."

  "So yer beam the information from there—" Star paused.

  "You've got it," John said quietly. "We have all sorts of computing power on Sky City. But there's not much on Cusp Station. The minimum distance between Sky City and Cusp Station is more than a hundred thousand kilometers. That's more than a third of a second for a one-way signal, two-thirds of a second round trip. Far too long."

  There was a long silence, broken by Wilmer. "We've got some time, a few weeks. Ship computers out to Cusp Station, enough to do the job."

  "Amanda?" John Hyslop raised his eyebrows.

  She shook her head. "Sorry. The computing system here is integrated and distributed through the whole of Sky City. We have plenty of spare capacity, but it's impossible to pull part of it out without screwing up everything. Air, water, waste disposal—the systems all call on the same computing resources."

  Star flopped down on the floor and sat with her legs sprawled inelegantly wide. She leaned forward like a gymnast, touched the carpet three times with her forehead, sat up, and said, "Then we are buggered. Any chance we can get enough computer power shipped up from Earth?"

  "Possibly." Bruno Colombo had sat silent through the whole long meeting. Most of the time his eyes were closed. John had wondered if the director was even awake.

  "Possibly," Colombo repeated. "But it's not an answer that I—or anyone—would be happy with. Either we'd have to ship people up from Earth who know their own systems well but are not used to working in space, or else our staff would be faced with the task of learning unfamiliar equipment and programming intricate life-or-death calculations in a very short time. Not just life-or-death for us. For everyone."

  "Even so," Wilmer said, "it's our best shot. I can promise you, even if the old shield were finished and working perfectly, the particle bundles we're talking about will go through it like it's not there. We need computer power on Cusp Station, lots of it. If the only place we can find it is on Earth, that's where we take it from. I know Celine Tanaka, I'm sure she'll cooperate."

  "Maybe she would." Bruno Colombo
stood up. Suddenly he had gone from being a bystander to the person in control of the meeting. "But I don't think that's the best answer. Hyslop? You know Sky City as well as I do, maybe better. Can it be done?"

  "I have to check. It will involve accelerations and stresses beyond any that were ever dreamed of. But my gut guess is that yes, we can do it."

  "Do what?" Star was still on the floor, but now she was sitting bolt upright and scowling. "What are you two going on about?"

  "If the mountain will not come to Mahomet . . ." Bruno Colombo turned to John. "Hyslop, you and the others here work out the engineering details. I'll start on resource allocation. Even if it is possible, it's not going to be easy."

  He hurried out of the room. John felt an odd mixture of irritation and admiration. Just when you were convinced that Bruno Colombo was nothing but a big bag of wind dressed in an expensive suit, he did something to prove that deep inside the pomaded head sat a highly creative brain. Sure, part of it was Colombo protecting his territory—but he also happened to be proposing the only possible solution. And then he left you to "work out the details."

  John found himself once more running the meeting. "It's going to be an interesting few weeks," he said. "We need loads of computers out near Cusp Station. We have all kinds of computational power here, but we can't ship it anywhere else."

  "So Mahomet . . ." Will Davis said.

  "That's right." In spite of the enormous size of the problem, John felt the thrill of a new technical challenge. "We're heading for the front line—all of us. We'll take this place and fly it all the way out to Cusp Station. And then, assuming that Sky City doesn't disintegrate on the way, and certain people stay out of our hair"—he stared at Star Vjansander, who was grinning at him in delight—"well, then we'll find out if certain harebrained ideas are anywhere close to reality."

  18

  The face of the man who wanted to see Maddy was familiar, even if she could not attach a name to it. He was—somehow she was not surprised—the sallow, dark-haired man she had seen on the shuttle up. He was leaning nonchalantly against the wall outside, holding under his left arm the same cylindrical black bag with its pink and mauve lining.

  He greeted her casually, as though they were old acquaintances.

  "I've seen you a coupla times round The Flaunt, and I recognized you on the flight up. You're Maddy Wheatstone. I'm Seth Parsigian. You an' me got the same boss."

  "The same boss?" Maddy wasn't ready to give anything away.

  "Mister you-know-who. The toxic midget."

  In spite of herself, Maddy smiled. "I bet you don't call him that to his face. Do you have identification?"

  He did not speak, but he slipped a card from his jacket and passed it to her. He waited as she placed it face-to-face with her own Argos Group card and his image flashed onto its back face.

  He raised one dark eyebrow. "Satisfied?"

  "Not yet. It doesn't state your division."

  "It wouldn't. I'm Special Projects." He grinned at her. "And just to prove that I'm Special Projects, try this one."

  He passed a second card to her. Her ID tracer showed the same picture and the same name, Seth Parsigian; but now he was identified as an undersecretary in the French armed services.

  He said cheerfully, "I've got three or four more if you want to see 'em."

  "Don't bother. So you're Seth Parsigian, and you work in Special Projects for you-know-who. I'm here on a special assignment, too. I don't have time for social chat."

  "Good. 'Cause this ain't one." He tucked away the cards. "I need help. If you can do something for me, I'll owe you big-time."

  The rules within the Argos Group were quite clear: You helped another member if you could, but not at the price of your own assignment. Another's success would not balance your failure.

  There was one exception. "Did GR tell you to ask me to help?"

  "Hell, no. If Gordy knew that you and I were even talking, he'd shit bricks."

  "Then we shouldn't talk." But Maddy didn't turn and walk away. An ally inside the Argos Group—especially one in Special Projects—might have many uses.

  He was watching her with those light, flickering eyes. She had the feeling that he had surveyed her up and down in the first second, made his assessment, and was acting on it.

  "Why don't I tell you my problem?" he asked. "I'll be real quick, no more than five minutes. Then you can decide if you'll help or not."

  "I'll give you two minutes."

  "Fair enough. I've come up here to find the person who killed a dozen teenagers. You know about 'em?"

  Maddy thought of Lucille DeNorville's ravaged body. "I know too much. I was there when we found one this afternoon. It was horrible."

  "So that's what all the excitement was around security. Another one? He's killed again?"

  "No. This was the body of one of the earlier victims, a girl called Lucille DeNorville."

  "I remember her. Number seven. Disappeared, but evidence at the scene said she'd had her brains bashed in."

  "She had. That and—other things. She'd been badly cut up." Maddy found that she couldn't add details. She went on, "Look, if I could help you, I would. But I don't know much about the murders. You need an expert."

  "I've got me an expert. No, I won't say who, so don't even ask. I'm up here tryin' to do the legwork, but it's damn nigh impossible."

  "Why? I've been anywhere I wanted to on Sky City. Nobody has bothered me."

  "That's because you're a woman. They'll leave you alone. Try bein' an adult male. A man like me, a stranger to Sky City wanderin' round by himself, six people ask who you are and tell you to move on every time you stop to scratch your ass."

  Maddy could see why. Seth Parsigian did not have the look of a man she would like to meet in a dark alley, and Sky City was full of dimly lit, empty corridors. She said, "I can't do legwork for you. I wouldn't know how."

  "I'm not askin' you to. All I'm saying is, if you were with me when I was doin' walk-arounds, I'd not have amateur sherlocks trailin' me every step I take."

  "So you want me to go with you. How do I know you're not the murderer yourself?"

  "Trust me. No, I guess that dog won't run. Well, for starters you can check the dates of the murders. You'll find I wasn't on Sky City for any of them."

  "I think I'll do that. Now you've had your two minutes, and more."

  "An' you're still here."

  "I want to talk payback. Suppose I decide to help you. What do I get out of it? What's in it for me?"

  "You sound like Gordy Rolfe. What do you want to get out of it? Can I do somethin' for your job up here? Tit for tat?"

  At the beginning of the meeting Maddy would have denied that she needed help. It took only half a second to realize how wrong that was. She had been told to stick with John Hyslop every second of every day. In practice that was impossible. She wasn't with him now, for instance, and she didn't know where he was or what he was doing.

  She made her decision. "You may be able to help me keep an eye on someone up here—someone whose actions are of direct interest to Gordy Rolfe. Do you know John Hyslop?"

  "I know who he is. He's the big-wheel engineer for Sky City and the shield. But I don't know him know him."

  "Gordy assigned me to watch him, see what he does. I could introduce you. Tit for tat. I help you poke around Sky City, you help me keep an eye on Hyslop."

  "Suppose he won't let me?"

  "Let me handle that end."

  "You say Gordy knows about this?"

  "He'll approve. Do you have your communicator hooked into the local system so I can get in touch with you?"

  "Give me ten minutes, and I will have."

  "Good. I'll call you. If I decide we have a deal, I'll tell you where and when we meet Hyslop."

  "You want to check me out first."

  "Of course. Do you mind?"

  He grinned. "I'd mind more if you didn't. You got a hell of a reputation in Argos—yeah, I've seen your file, did that afte
r I spotted you on the shuttle up. But files can be faked, and there's too many amateurs in this game already." He turned away and said over his shoulder, "Call me, Maddy Wheatstone. Professionals need to stick together."

  * * *

  A tedious and interminable search of the information banks, both on Sky City and Earthside, found no sign of a Seth Parsigian. No one in the Argos Group matched his detailed description. Maddy was not too surprised. You could look at it the other way round: Anyone in Special Projects who could be traced was not right for the job.

  When she finally headed for Bruno Colombo's office, John Hyslop was no longer there. Colombo himself was busy in a meeting and unavailable. Goldy Jensen, asked to provide information, was not cooperative.

  She looked up from her immaculate desk in the outer office and frowned at Maddy's question. "I don't keep track of everybody on Sky City, you know."

  "It's important that I locate John Hyslop."

  "Important to whom? I suppose you might try the engineering information center. He spends a lot of time there."

  "Where is that?"

  "Any of the directories will tell you how to reach it." Goldy turned impatiently away and initiated another call to Earth on Bruno Colombo's behalf. Five lines were already active and two others blinked for attention.

  Maddy knew she would get no farther with Goldy. And yet today's rudeness did not feel deliberate. It was more as if Goldy Jensen was working under unusual pressure and had no time for her normal discourtesy.

  The feeling of pressure persisted as Maddy used a directory to find the location of the engineering information center and made her way toward it. Everyone she passed gave off an impression of urgency. Something important was going on inside Sky City. Everybody but Maddy seemed to know what it was.

  As she moved upward toward the lower-numbered levels—the engineering information center, to her surprise, lay far from Bruno Colombo's office and close to the axis of Sky City—she left a message for Seth Parsigian. He was to meet her in an hour unless she called and canceled. The limited information in her Argos data base confirmed Seth's position, but it did not indicate that he knew anything about space activities. Rather the opposite. Like Maddy, he was ground-based. It added to the mystery of his presence. Why would Gordy Rolfe send his Special Projects head to look for a murderer out here?