"Just knowing he's alive is good news enough," Betsy assured him. She thought for a moment. "What if we could cut the whole chair loose? Is there enough room behind him to move the chair back and get him out that way?"

"Uh... I think so, yes. But I don't know what we would do after that. I heard the flight attendant say the door was jammed."

Betsy frowned. Rayburn hadn't mentioned that to her. "We might be able to force it open anyway and get it connected to the rest of the Skyport. Are the rest of the passengers all right?"

"A few minor injuries, mostly bruises due to the safety belts. We've been very lucky."

So far. "Yeah. Thank you, Doctor. Please let us know immediately if there's any change."

"Got the prints, Betsy," Lewis called as she turned off the mike. "I'm heading down."

He was gone before she could do more than nod assent, leaving her and Henson alone. For some reason the empty seats bothered her, and she briefly considered calling in some of Seven's off-duty crewmen. But as long as they were stuck in this virtual holding pattern, extra help on the flight deck would be pretty superfluous. Turning back to the instrument panel, she felt a wave of frustration wash over her. So many unanswered questions, most of them crucial to the safety of one or more groups of people aboard the Skyport—and she was temporarily at a loss to handle any of them. For the moment there was nothing she could do but try and line up the problems in some sort of logical order: if A is true then B must be done, and D cannot precede either B or C. But it was like juggling or playing chess in her head; there were just too many contingencies that had to be taken into account every step of the way.

Behind her the door opened, and she turned to see two men walk in. One she knew: Paul Marinos, captain of Wing Section Six. The other, a thirtyish young man in a three-piece suit, she'd never seen before. But she knew instantly who he was.

"Betsy," Marinos said, "this is Peter Whitney, of McDonnell Douglas."

—

Whitney had been daydreaming in his lounge chair, enjoying the unique Skyport atmosphere, when the violent bump jerked him back to full alertness. He shot a rapid glance around the room, half expecting to see the walls caving in around him. But everything looked normal. Up ahead, he could hear muttered curses from the dining room—prompted, no doubt, by spilled coffee and the like—while from the lounge itself came a heightened buzz of conversation. Whitney closed his ears to it all as best he could, straining instead to listen for some clue as to what had happened. An explosive misfire in one of the engines was his first gut-level guess; but the dull background rumble seemed unchanged. A hydraulic or fuel line that had broken with that much force might still be leaking audibly; again, he could hear nothing that sounded like that. Had there been that bogey of the '70s and early '80s, a mid-air collision? But even small planes these days were supposed to be equipped with the Bendix-Honeywell transponder system—and how could any pilot fail to see the Skyport in the first place?

The minutes dragged by, and conversational levels gradually returned to normal as the other passengers apparently decided that nothing serious had happened. Whitney suspected differently, and to him the loudspeaker's silence was increasingly ominous. Something serious had happened, and the captain was either afraid to tell the passengers what it was or the crew was just too damn busy fighting the problem to talk. Neither possibility was a pleasant one.

A flash of royal blue caught the corner of his eye, and he turned to see a chunky man in a Skyport-crew jumpsuit step from the dining area into the lounge. The flight attendant who'd served Whitney's breakfast was with him, and Whitney watched curiously as her gaze swept the room. It wasn't until she pointed in his direction and the two started toward him that it occurred to Whitney that they might be looking for him. Even then uncertainty kept him in his seat until there was no doubt as to their target, and he had barely enough time to stand up before they reached him.

"Mr. Whitney?" the jumpsuited man asked. His expression was worried, his tone was politeness laminated on urgency. The girl looked worried, too.

Whitney nodded, noticing for the first time the gold wings-in-a-circle pins on his chest and shoulderboards. A wing captain, not just a random crew member. Whitney's first hopeful thought, that this was somehow related to the tour he'd asked for, vanished like tax money in Washington.

"I'm Captain Paul Marinos," the other introduced himself. "We have a problem, Mr. Whitney, that we hope you can help us with. Is it true that you work with computer systems for McDonnell Douglas?"

Whitney nodded, feeling strangely tongue-tied, but finally getting his brain into gear. They were almost certainly not interested in just general computer knowledge; his nodded affirmative needed a qualifier added to it. "I know only a little about current Skyport programming, though," he told them. "I mostly work with second-generation research."

Marinos's expression didn't change, but his next words were almost a whisper. "What we need is a malfunction check on our shuttle approach and guidance equipment. Can you do that?"

The pieces clicked almost audibly into place in Whitney's mind. It had been a crash, and one that all the Bendix-Honeywell collision-proofing in the world couldn't prevent. "I don't know, but I can try. Where do I find a terminal?"

"On Seven," was the cryptic response. "Come with me, please."

Marinos led the way across the lounge and back into the dining room. A door in the right-hand wall brought them into one of the module's food preparation and storage areas. The blonde flight attendant left them at that point; moving forward through the galley, Marinos and Whitney arrived at an elevator. One deck up was a somewhat cramped hallway lined with doors—crew quarters, Whitney assumed. In the opposite direction a heavy, positive-sealing door stood across their path. Marinos unlocked it and swung it open; and to Whitney's mild surprise an identical door, hung the opposite way, faced them. The captain opened this one, too, and gestured Whitney through, sealing both doors again behind them. "We're on Wing Section Seven now," he told Whitney, leading the way down a hall that mirror-imaged the one they'd just left. "The wing captain here is Betsy Kyser. You'll be working with her and her crew."

Beyond the hallway was a small lounge; passing through it, they entered what appeared to be a ready-room sort of place with a half-dozen jumpsuited men and women listening intently to an intercom speaker; and finally, they reached the flight deck.

"We appreciate your coming up here," Captain Kyser said as Marinos concluded the introductions. "I hope you can help us."

"So do I," Whitney said. "Anything at all you can tell me about your malfunction? It might help my search."

"All we know is that it's somewhere in the equipment or programming that guides shuttles into the docking bay." In a few terse sentences she told him what was known about the shuttle crash, including the craft's current orientation in the bay. "My indicator said its approach velocity was too high, if that's significant," she concluded. "But I don't know if that was just my indicator or if the whole system was confused."

"The shuttle's radar is independent of your equipment, though, isn't it? Maybe the pilot can corroborate your readings."

"Maybe—but if he'd seen anything wrong he'd almost certainly have yelled. But I'll ask him. First, though, I want to get you started. Paul, will you monitor the shuttle?"

Marinos, who had already quietly seated himself in the copilot's seat, nodded and put on a headset. Kyser removed her own and led Whitney to a console built snugly into the flight desk's left rear corner. Motioning him into the chair in front of it, she leaned over him and tapped at the keys. "Here's the sign-on... access code... and program file." A series of names and numbers appeared on the screen. "Any of those look familiar?"