'Were his things missing?'

'Yes.' The diary, the technical papers, the flight bag, insulin kit. 'But they didn't find the thing that Koichi made.' The mask. 'I brought that away.'

'And you'll keep it with you.'

'Yes.'

Hell was he talking about, there was only one man in this world the mask would fit and he was gone and it looked unlikely we'd ever see him again.

'You told the abbot?'

'Yes.'

Brought them away from their prayers, the abbot and the interpreter, committing a sacrilege I've no doubt, their sandals scuffing the earth floor, their robes sickly with the smell of incense, the abbot's eyes wide as I told him, his hands going at once to his beads.

'Ni kendin Bian shile?'

The interpreter looked at me. 'You are sure that Bian is dead?'

'Yes. I'm sorry.'

'Xingyu xianshen, ta met shi?'

'I don't know. They came for him, but I doubt if it was to kill him later.'

The abbot spoke to the interpreter, who turned and called two other monks away from their prayers; they passed us with shock in their eyes, their robes flying as they hurried across the main floor to the ladder in the corner.

In a moment I said, 'Your Holiness, I imagine there are monks here who joined you not so long ago, people you don't know very well as yet. Do you think anyone like that could have betrayed Dr Xingyu?'

For an instant he looked appalled, then said through the interpreter: 'Only four of us knew about our guest. Only four.'

The abbot himself, the interpreter, Bian, and the monk who'd shared duty with him.

'The man who helped Bian.' I said, 'did you know him well?'

'But of course. It was a great responsibility I gave him.'

I left it at that, didn't ask if this man might have talked to anyone else here. It wouldn't have been easy for those who knew about this eminent guest of theirs to keep silent. This was a small sect, and the messiah was in their house.

I told Pepperidge this much, and then for a moment there was nothing on the line but crackling. Then he said, 'That could have been what happened, yes. People talked, someone chose to betray him. But they didn't go to the police.'

'No.' Xingyu hadn't been taken by the police, the PSB, the KCCPC, or the military, or there would have been jeeps raising the dust outside this place and shouting and the tramp of boots and Xingyu would have been hustled away with his wrists bound and his feet dragging, the abbot too, summary trial and execution. 'It wasn't the police,' I said, 'who took him, or anyone official. It was a private cell.'

And this was the worst of it. I hadn't told Chong on the way south in the night; he was support, not executive; his job was to provide manpower, pass information, liaise with the director in the field, protect the shadow, blow up sergeants. Support people must be told even less than the executives because they're more vulnerable, more in danger of capture and interrogation.

I wouldn't have told him in any case; he was frustrated enough as it was. But this was what we faced now: we hadn't just got the police and the Public Service Bureau and Chinese Intelligence and the People's Liberation Army to deal with. Somewhere in Lhasa, in the streets, behind the walls, behind the doors, in the shadows, there was a private cell operating, professional, effective, and with powerful political backing, or they wouldn't have targeted a man like Xingyu Baibing, and this was the worst of it because the forces of vast organizations like the police and the military have got the advantage in numbers and equipment and information resources and it's often difficult to keep out of their way, but at least you know where they are and what they look like, you can see them coming.

A private cell is different. You can be standing next to a man in a bar or a hotel or an airport and not know that you're in hazard, not know that your mission has been infiltrated and that you'll crash if you're lucky or be found dead by morning if you're not.

A private cell can work in the dark, in silence and in stealth. Its power to destroy the opposition is not paraded, like that of a rattlesnake, but shrouded, like that of the black widow.

We were the opposition.

'Do you think' — Pepperidge on the line — 'that someone is just trying to make some money?'

Xingyu would have a price on his head, a big one.

'No. The people who took him were professionals, not mercenaries, not terrorists.' It had been done with great expertise: they'd not only succeeded in finding Xingyu Baibing but they'd gone into a monastery full of monks and got out again with the man they wanted, killing silently and disturbing no one.

Chong was getting out of his cab, looking along the road, looking at me, his gloved hands palm down, pressing the air, don't worry, just keep a low profile, stay where you are, don't come into the street.

I told him I'd gone to ground, but going to ground doesn't necessarily mean that you've got to bury yourself in a cellar, though it might come to that if it's the only way to survive the field and finally get out and go home; it normally means you've got to keep off the streets if you can, stay away from hotels and taxis and airports, watch for the police every minute you're exposed and be ready to duck and run and wait things out if they see you. It's a status we loathe and fear because it can only get more dangerous as time goes by.

They knew my name at the Public Service Bureau: they'd checked my papers there and asked Su-May Wang if she knew where I was. The police would have been alerted as a routine procedure and I'd given my passport and visa to Pepperidge in the cafe because if I were stopped on the street I couldn't show them, would have to say I'd lost them and then try to get clear before they took me along to the station for an inquiry: you cannot, in a town where martial law obtains, go without papers.

Pressing his hands down, Chong, everything's under control, his breath clouding on the raw morning air as the light in the east took on more colour, pouring gold along the horizon.

'Do they want the subject,' Pepperidge asked, 'or what he's got in his head?'

Not after facts now, simply tapping me for what he could get, for what I could give him, because London would ask these questions and he'd need answers. 'If all they wanted was information,' I said, 'they'd have gone for me, not him.' Information on Bamboo, the information I'd been forced to give Xingyu to keep him from running home to Beijing.

'So what do they want him for?'

I had to think, but it wasn't easy, the cold was like a clamp, numbing the body, numbing the brain, not cold so much as fatigue, been a hard day last night. 'They want him,' I said, 'for bargaining, perhaps. As a hostage.' There were a lot of possible scenarios with Xingyu Baibing as the catalyst, brought forward to bring political pressure, a guarantee, a bargaining chip, a martyr to bring the weight of the people against the Chinese government.

'They can't do anything with him here.'

'No. They'll have to take him to Beijing.'

'But they can't do that.' His voice kept fading, coming back. 'Any more than we could have, now that he's being actively sought. In a moment, 'What is your situation?'

'Ground. Chong's still in support.' I told him about the roadblocks, the sergeant.

'Can you still use the truck?'

'Yes.' The sergeant wouldn't have seen it distinctly enough from the roadblock to identify it as a green Jeifang, and the most he would've said to anyone would have been that there was a vehicle on the move down there, he'd go and check it out.

'If they were searching vehicles,' Pepperidge said, 'it couldn't have been a coincidence. Someone must have told them you were going to him.' A beat. 'They're very close, aren't they?'