Central Siberia, 37,000 feet, 0417 UTC

British Pacific Flight 172 had left Tokyo for London Heathrow right on schedule, every one of its 332 seats occupied, every ounce of weight, every moment of balance accurately calculated. The route was standard these days: no more long, circuitous detours to avoid the Soviet Union, no more boring stopovers in Anchorage. Just a sharp hook to the west after takeoff, on to Vladivostok, and then a dead straight line along the great circle, coming down over Finland into Britain over the North Sea.

This was a two-man operation: one captain, one first officer, both watching the LCD screens of the new all-digital flight panel and relying, for the most part, on the autopilot to guide the plane's movements.

Ian Seabright didn't like to admit it to anyone, particularly the company's inquisitive human resources staff, but these days flying just plain bored him. It had been different when he first got into the game, straight from the RAF, in the seventies. Then you used your brain, sometimes your muscle, too. Today you just minded the computer, watching the dials flash and alter on some screen, making sure the silicon pilot didn't do anything wrong.

He was fifty-three, in reasonable health, a little overweight from all those long-haul stops in hotels where the food was free and there was precious little else to do. The first officer was Jimmy Mulligan, a bright, red-haired Irishman who'd worked his way onto the flight deck the hard way, through a private pilot's license and then a low-paying gig as a flight instructor in the States. Seabright liked Mulligan. The man was smart, polite, hardworking. And yet, at just pushing thirty, he was already starting to look bored. Seabright, only two years from retirement, didn't envy him-- with nothing to look forward to but this tedious round of routine. The idea of all those wasted hours in the cockpit appalled him.

Seabright looked at the moving map on the GPS. They were nine hours out now, cruising in still air at 37,000 feet in the middle of nowhere with the weather looking fine and sunny all the way, every inch of the route in daylight, straight into Heathrow. Out of the window some godforsaken part of Russia passed by slowly, even with a ground speed of 530 knots. A piece of nothingness in western Siberia, he guessed.

"You going to marry that girl, Jimmy?"

The Irishman smiled. "You mean Ali?"

"I believe that was the young lady you seemed to be proposing to last night."

Mulligan thought about it. "You think she took it that way?"

Seabright closed his eyes and thought: They can fill these damn things with all the computers they want, but this little ritual won't ever go away. You just coop up a crew in some foreign hotel, leave them there for three days, and see what happens.

"She's sweet, all right," Mulligan said. "A guy could do a lot worse."

"A lot worse," Seabright agreed.

"Which makes a guy think, well, maybe he could do a lot better?"

Seabright stared at Mulligan and wondered why this short, meaningless exchange sparked a little flame of anger inside him. It all just comes around, he thought. There are things you can never tell another man. You just have to wait, let him discover it all for himself, then look him in the eye and say: Yes, me too. The casual drift from bed-hopping first officer to married (happily or otherwise) captain was one such journey.

"Looks like we've got company," Mulligan said, staring out over the starboard wing. Seabright followed his gaze. A good ten miles off, on a parallel course tracking the same flight level, was a white 747 with imperceptible markings on the side. He dialed up the inflight frequency and put out a call. There was no reply.

"Bastards," Mulligan muttered, reaching for a pair of pocket binoculars in the seat pocket. Then he focused on the distant shape and let out a low, sweeping whistle.

"Jimmy?"

The first officer took away the glasses from his face. "Sir, wasn't there something in the paper about a summit in Tokyo? Lots of VIPs expected to be flying out?"

"Why do you think we're packing them into every square inch we've got right now? There was a world summit. Ended yesterday."

"Well," Mulligan replied, passing over the binoculars, "it looks like we've got the American President himself on our wing. Can't expect those chaps to talk to the likes of us, now, can you?"

Seabright looked at the long white shape of Air Force One through the glasses. This was a new one for the book.

"I think you're right there...."

Then he snatched the instrument away from his face in a rapid involuntary physical jerk, feeling, for a moment, as if his upper torso were in spasm. The pain was sudden, sharp, and intense. And he wasn't alone. Next to him Mulligan was moaning. He had his hand to his forehead, eyes closed.

"You okay, Jimmy?" This was unlike him. Mulligan never swore, never complained about anything. The first officer rubbed his head for a moment or two, then unclenched his eyes and looked at Seabright. His eyes were more than a little pink, unfocused, watery too.

"Damn headache," Mulligan complained. "Came straight on me like that. Just my turn to get one, I guess."

"Sure."

Seabright knew he had the makings of one himself. And the tension of the sudden muscle spasm had not gone away entirely either. His gaze shifted to the display panel. "Looks like you've got an amber alert light on the main gear, Jimmy. Nothing to worry about, I'm sure, but take a look."

"Sir... ow!"

And the strange thing was, Seabright felt it too. A sharp, stabbing pain in the right temple, so hard it made him wince, just like Mulligan. Then it went away as quickly as it came, leaving a dull throb behind.

"What the hell was that?"

Seabright wiped his forehead, felt the sweat there, scanned the panel as he ran through the possibilities.

"You check the cabin pressure too, Jimmy. I got that pain as well and I don't think we're both imagining it."

They scrutinized the dials, went through the routines they knew by heart, and confirmed the pressure, stable at the equivalent of 6,000 feet.

"You think it could have dropped, just momentarily, without us noticing it?"

Mulligan's face was close to the color of his hair, and Ian Seabright felt, deep in his gut, something hard and cold and angry start to knot there and wait for him to recognize it.

"No," he replied. "That's just not possible."

"I can pull out a record of the pressure if you like. See if it took a sudden drop."

Seabright nodded, just for something to do, knowing this really wasn't the cause of it, knowing the pressurization system was behaving just as it should.

Mulligan punched away at the control deck, watched the displays shift and change on the color LCD screen. When he finished, he only looked more baffled. "Maybe it was one of those things," he said, wanting to take back the words the moment he said them.

Seabright nodded and neither of them needed to say it, the phrases just passed unspoken between them, the old pilot's doggerel they drilled into you year after year. All those half-smart, half-true little maxims ran through both men's heads at that moment... that there really is no limit to how bad things can get, and how you shouldn't believe in miracles, you should rely on them. And, in particular this one: When in doubt, predict that the trend will continue.

They sat in silence, in trepidation, and then they heard the security key turn in the cabin door and saw Ali Fitzgerald walk through, her face white and pale. The very appearance of her made the knot in Seabright's stomach turn on itself once more until this tangle of pain in his gut was rock-hard, icy and immobile.

"We've got a medical out there," she said, and Seabright could see how close she was to real panic. "It's a bad one, sir, and I already asked. There's not a doctor on the plane."

Seabright stared hard at his first officer, checked the panel and made sure nothing else was blinking there except the one errant amber light on the main gear.

"You okay on your own, Jimmy? Don't just say yes. Think about this. I don't want more than one emergency on my ship."

Mulligan thought before he answered; he knew the old man would demand that.

"I'll be fine. Best leave the door unlocked anyway."

"Yes," Seabright said, then unstrapped the shoulder harness, pulled himself out of the left-hand seat, and followed the stewardess to the door, held it half-closed, not letting her through.

"Sir?" She looked into his face, not understanding, not far from the edge, he thought, not far at all.

"Ali," he said, as quietly, as gently as he could "Your shirt. You need to change it. You need to put a jacket on. Something. You can't go back through the cabin like that."

She looked at herself, at the broad red bloodstain that marked the entire front of her white blouse, down onto her skirt, marked her skin too, around her neck, where she'd held the man's head, trying to do something, trying to do anything.

"No, sir," she said, then waited for him to open the door, stepped behind the bulkhead that separated them from the first-class cabin, and pulled out a clothes carrier. It happened so quickly he scarcely had time to tear his eyes away. She tore off the blouse, then the skirt, washed her neck and forearms rapidly with a damp Kleenex and a bottle of Malvern water, and put on the dirty uniform she was carrying back from the outward journey.

"He's in business, sir. We've got the medical kit."

"Good," Seabright answered, and watched her step in front of him, turn in to the first-class cabin, smooth down her dress, start to do her job.

He followed her down the aisle, felt the eyes on him, the tension in the seats, and thought to himself that Jimmy Mulligan could do a lot worse. A hell of a lot worse if he wanted to.