“Yes,” admitted Hayden. “Yes, I did. And it worked.”

“Really?” One eyebrow expressively tilted.

“Really,” confirmed Hayden. “What it said in the magazine? Miracle cure? They weren’t exaggerating. Like turning a switch, and the pain just wasn’t there any more. One dab of the gel, and . . . wow.” Unconsciously, beneath the face-mask, he smiled at the memory.

“It’s never quite as simple as ‘wow’,” Dr. Pang informed him sternly. “There has been considerable trepidation as to possible side effects of your ‘miracle treatment,’ to say nothing of the ethical dimension of this new research in transgenics. Observations among the trial groups have pointed up several areas of grave concern—”

“Oh, I know,” said Hayden, lying back in the chair and scratching his masked jaw ruminatively. “It’s not as if there haven’t been some side-effects . . . ”

But who cared, if it wasn’t hurting any more? Which it wasn’t; he rubbed on gel from the tube, and the gel worked. It was cold going on, a snowball in the face, and within seconds you could feel it going to work, numbing, soothing; ah. Before he got back to the hotel he realised, with a sort of delirious disbelief, that he was pain-free. Experimentally he mouthed the words. His tooth didn’t go ow. He said them aloud, until the taxi driver turned round. Regally, Hayden waved away his curious stare.

No pain for Hayden that night, and for the whole of the marvellous day that followed. He slept in—he slept! and it didn’t hurt—he slept in late, skipping his eight-thirty the following morning in favour of a lie-in, a long hot shower, and an extra pot of coffee brought up to his room. And he drank the coffee, and his tooth didn’t hurt any more. And he looked out of the window at the sun above the harbour, and no toothache. And he stuck his finger in his mouth, and the swelling had already gone down. It was fine.

The idea was that the gel would hold him till he got back to London, where his own dentist, a melancholy Welshman called Llewelyn, could deal with the tooth, cap it or drill it or yank it out. Whatever. That was one for the future, and Hayden was too busy relishing Hong Kong sans the agony. Padding across the room in bare feet, a lordly beast returning to its lair, he caught sight of himself in the mirror: his grin looked like something Jack Nicholson might sport at the winding-up of a particularly glorious orgy.

First thing on waking up, quite late in the afternoon; more gel. Mmmm. Rub it in, all nice and analgesic. And something to eat; Christ he was hungry. Big hairy lumberjack portions, now, straightaway. He started to call room service, but halfway through he changed his mind, and bounded into the shower instead. Bathed and dressed, he loped down to the lobby in search of a taxi.

By the time Hayden was disembarking at Causeway Bay all the businesses on the island were emptying out, each office block disgorging its load of commuter ants to jam up the streets below. Hayden took a deep breath and launched himself into the crowd, but his way seemed surprisingly easy; as if space were being cleared for him, somehow.

He dived into the first restaurant he saw, a gleaming twenty-first century chow-parlour which seemed to be called the Futuristic Dragon. There he ordered up plate after plate of good things, all the protein he’d been denied over the last few days. Already all of that was starting to feel like a nightmare he’d once had, years and years ago. So complete was the current absence of pain, it seemed almost ludicrous to think that only yesterday he’d been desperate, maddened, panicking like a rat in a trap . . . hah. Absolutely ludicrous. He laughed out loud; some of the other diners glanced over before hastily averting their gazes. Supremely indifferent to everything except the contents of the platter laid before him, Hayden tore in to the exquisite char sui pork.

Several meat courses and the best part of an hour later, Hayden untucked his napkin and pushed his chair back from the table. Sated for the time being, he felt like strolling some of his dinner off.

Though still busy by Western standards, the streets were appreciably less insane by the time he was stepping out in the direction of the Mid-levels. Pedestrians own the city, thought Hayden contentedly; car drivers slide through it untouched and unenlightened, subways are just burrows. Pedestrians lay claim to all the spaces; they flow through the arteries of the city and the city flows through them. As if to prove it, he took an unnecessary turn left at the next junction, following a sign that said Happy Valley. How long had it been since he’d walked anywhere just for fun?

For the next few blocks Hayden let chance determine his route. This he did by selecting, more or less at random, various passers-by, and following very close behind them, matching his stride exactly to their own, sometimes less than an arm’s length away. As soon as they became aware of his presence, he would drop off, and select a new target. The fourth or fifth of his marks rumbled him almost immediately, though; they’d gone only a few paces when the man in front, a portly, respectable-looking type in a three-piece suit and, improbably, a white solar topee, suddenly became aware of Hayden’s presence. He turned, saw Hayden falling back just a moment too late, and unloosed a string of indignant abuse in a hoarse high register. Along the street, people glanced in their direction, then turned, either incuriously or prudently, away. A couple of schoolgirls in pleated skirts and St. Trinian’s straw boaters had seen what Hayden was up to some blocks back; smothering their laughter behind their hands, they were filming this latest altercation on their videophones. When they realised Hayden was looking at them, they screamed and ran away, gwailo, gwailo. With no immediate object in mind, Hayden followed them for a while.

By the time they’d vanished into some glitteringly meretricious megastore or other, he had no idea how far away from the hotel he was. His various diversions had led him uphill, which he supposed meant south and away from the harbour. Probably he was somewhere above Happy Valley by now, near Aberdeen Park perhaps, still a good few miles away from his hotel. Not that he was bothered: it was good just to walk, to stretch the muscles in his legs and fill his lungs with unprocessed air. He breathed in deep, relishing the stink of charcoal braziers and the savoury smell of street food, all the jostling aromas of a strange new city at dusk. He consulted the rising moon, and decided his hotel ought to lie in that direction. As he set off, three shadows subtracted themselves from the gloom of a nearby shop doorway and followed him.

Perhaps a mile later, Hayden found himself on the outskirts of some sort of public space, a closely planted grove of trees and bushes that fell away precipitately down the hillside. Beyond the topmost branches of the trees he could see the harbour down below, even pick out the landing lights of helicopters like fireflies round the cargo bays at Kai Tak. Hayden supposed he could waste time going round the park, or else he could just barrel right through it. Confidently—see what valorous animals we can be, when we’re only free of pain?—Hayden set off along the path.

Underfoot was hard compacted sand, no slips, no trips. Even when the branches of the trees closed above his head, there was still enough moonlight for him to pick his way. (Had his night vision always been so acute? Damn, he was in good shape. Queue forms to the left, ladies.) The path wound down the hillside, till it was blocked all of a sudden by a wrought-iron gate set in a high hedge. Private property? Hayden thought not; and in any case the gate opened to his touch.

Inside was a small burial ground, very compact and quite grown-over. Small family shrines in serried ranks, with here and there a votive candle burning; white marble ghostly in the moonlight, and black tangles of bracken between the slabs. Hayden stepped into the enclosure, closing the creaky gate behind him. Somewhere in the bushes, a nightbird sang out in alarm. There were flights of steps between the terraces; in no particular hurry, Hayden sat down and lit a cigarette. Behind him, the iron gate creaked. Hayden turned round. He had company among the dead.

Now for those of you who haven’t been in a fight recently (as Hayden explained to an increasingly bemused Dr. Pang), when it comes to mixing it the human male knows pretty much from the get-go how he’ll behave. He’ll either be emollient or abrasive, placatory or confrontational; he’ll flee or fight. There’s just something about the quality of the encounter that pre-determines these things—a hundred split-second decisions feeding into the adrenaline centres, instantaneous judgements based on the adversary’s appearance, one’s own state of preparedness, etc. And Hayden felt good tonight, dammit. He was enjoying his walk, and he did not appreciate being followed. And just in that moment, these simple factors outweighed any more practical considerations: the fact that there were three of them, young and lean and vicious, and that the leader was waving a flick-knife in front of him as he advanced. No matter: there was no way Hayden was just handing over his wallet and his watch and his iPhone. Not tonight, no sir.

Instead he found himself up on his feet in a curious sort of crouching pose, leaning forward on the balls of his feet, his head canted to a slight angle. The one in the front—mean-looking bastard in a leather jacket, hair flopping down across his brow—snarled and said something in Mandarin. The other two laughed. Hayden ignored them entirely, and took a few steps back, feeling with one outstretched foot for obstructions, never taking his eyes off the thug in front.