'Yes.'

'Then I'll take him, if he's willing. He's fluent in Chinese and the dialects.'

'Very well.'

'Do we need to get him here tonight?'

'No. We needed you here because you are the key. If you so choose.'

'If we can't get Pepperidge, who else is available?'

'No one,' Tilson said from across the desk, 'at your level.'

Hyde: 'If necessary, Mr Croder would direct you in the field.'

Croder. He was Chief of Signals. I was beginning to feel the size of this thing.

One of the phones rang and Tilson took it and said all right and rang off and looked up at Hyde. 'They're on their way over there now.'

Hyde angled his watch to the light. 'Very well.' He turned to me again. 'Have you any further conditions?'

Silence in the room.

We can always refuse a mission. It can be in a locale too far away for our liking, or too hot, too cold, too hostile, too dangerous. Or we can simply be too tired, too exhausted after the last time out; or we can feel the tug of intuition not to take it, this one, not to risk it. We grow old, in this trade, before our time; we grow canny, cunning, cynical, steeped in subterfuge, versed in stealth.

We grow obstinate, difficult; we grow intractable. And we grow afraid.

Their eyes on me, Tilson's, Hyde's, in the lamplight, in the silence of the room.

'No,' I said, 'there are no further conditions.'

Hyde broke his stare. 'You accept the mission?'

'Yes.'

'Then we must be going,' he said. 'We're to meet these people at the Foreign Office as soon as we can get there. Did you come in your car?'

'Yes.'

'Will you take me there?'

'Of course.'

'Taxis are so laggardly. Tilson, will you set everything up? I'll brief Quiller as soon as we're back, then you can put him through Clearance.'

On our way down Whitehall in the car, Hyde sat with his bulk hunched against the passenger door, watching the road and sometimes watching me as he talked.

'Go right here.' I turned into Victoria Street. 'Keep going,' he said.

'Not the Foreign Office?'

'We just said the Foreign Office, but actually no. Too many moles. This matter, you see, is rather important, and we don't want people listening. Since you are now committed, I can give you the whole thing in a nutshell. If all goes to plan, we should be able to overthrow the Communist regime in Beijing and establish a democratic government within a matter of days.'

There was the smell of burned metal from the high voltage contacts, and the black mouth of the tunnel was lit intermittently by the flash of a welder's torch; I suppose there was a night crew along there, working on the rails. Here on the platform the scene was more formal: most of the people were in dark overcoats and two of them had rolled umbrellas. I was in a polo sweater and padded bomber jacket, since they'd got me out of my flat in such a hurry.

There were some men hanging around the mouth of the tunnel and the archway to the escalators; on our way down here, Hyde had told me the scene was protected by plainclothes police. 'We mustn't be disturbed, you see. I suppose it's odd,' he'd said, 'that in order to avoid any moles we're going underground.'

It looked as if we were the last to arrive, and someone came forward to meet us.

'This is Mr Jones,' Hyde told him, and the other man shook hands with me and said:

'I'm Barstow, Private Secretary. Come and meet people.'

Another flash lit the tunnel, and there was the crackle of the welding flame.

Barstow took us over to the group and made the introductions. 'His Excellency Qiao Dejian, Ambassador from the People's Republic of China. The Right Honourable James Jarrow, Secretary of State for the United Kingdom. Mr William Glover, MI6. Mr Hou Jing, Chinese embassy counselor. This is Mr Hyde, and Mr Jones. Shall we go and sit down?'

There was a holdup because the Secretary of State wanted the Chinese ambassador to go into the coach first, and little Qiao couldn't possibly allow it, so Barstow managed to shepherd them discreetly side by side through the sliding doors and the rest of us shuffled after them, with Hyde and me in the rear. Hyde's official capacity hadn't been mentioned and 'Mr Jones' is generally understood among the diplomatic crowd to be a cover name for some kind of agent.

There was another holdup inside the coach because Ambassador Qiao wouldn't sit down until the Secretary had, but Jarrow finally took his seat halfway along the coach and everyone else followed suit and someone pulled the sliding doors together manually and took up guard duty on the platform outside. I noticed that Qiao was looking deathly tired and the Secretary of State wasn't looking particularly tired but certainly tense. The Chinese counsellor sat with a heavy black briefcase on his knees, clutching it with gloved hands.

Barstow, our Private Secretary, looked at his boss, and Jarrow nodded, but then there was another holdup while Ambassador Qiao got a handkerchief out and blew his nose and asked us to excuse him because he'd caught a cold. His English was perfect, I would have said Cambridge.

The scene was a degree surrealistic, and I think it put the Chinese off, being in a train underground instead of a nice formal office. The hand straps hung down above our heads like tiny gibbets in a row, and we could see our faces on his side reflected behind the people opposite, under the dim ceiling lights. The doors had been shut on us with a definitive thump and we looked as if we'd been thrown together in purgatory, without knowing where the train was going to take us, to heaven or hell.

Jarrow pulled out a gold cigarette case and asked if anybody minded and no one spoke so he lit up, and Barstow started talking.

'So that we all know what's going on, I'll recap the main points for you.' He sat forward on the seat, hands on his knees and feet together, looking from one face to the next and giving each of us a precisely allotted share of his cool blue eyes. 'Ambassador Qiao came to us two days ago and told us that after the democratic uprising in Beijing of last week, he feels he no longer wishes to represent the Communist regime at present in power there. His intention was to defect, and he asked us for asylum. His counsellor, Mr Hou Jing, has identical feelings. We conferred with MI6, who agreed it would be far more useful for all concerned if the ambassador remained at his post and made himself available to us as a source of information.'

Qiao sat slumped on the seat, but I didn't think he was going to doze off. A lot of his fatigue must have been due to stress: a couple of days ago he'd been a bona fide ambassador and now he was in effect an intelligence agent working for the West. He didn't look the type who'd commit an act of betrayal too easily.

'He and his counsellor declared themselves willing to do this,' Barstow said, his eyes resting on mine and passing on to Hyde's. 'The ambassador would probably like me to point out that in the present circumstances he regards his action as simply a shift of loyalties, from the Chinese government to the Chinese people.'

No one spoke, though I thought we should have clapped or something. Jarrow flicked ash from his cigarette, looking at nobody.

'Ambassador Qiao,' the Private Secretary went on, 'has conferred with the Prime Minister, who is therefore acquainted with the situation, and who has pledged her assistance in any way possible with the ambassador's proposals. Mr Hyde and Mr Jones were called upon, and have declared themselves ready to implement those proposals by whatever means are open to them. I need hardly say, gentlemen, that the most extreme discretion must be used by all those present, when we are no longer protected by the security measures we enjoy at the present time.'