'It was a confidential,' said Frank. 'My informant was someone who I can absolutely not name. If London, or the CIA office, demand details of the identification I will find myself having one of those wretched arguments that I hate so much.' He looked at me and I nodded. 'What do you think this fellow's here for, Bernard?'

'No one seems to be sure who Thurkettle works for. The prevailing wisdom – if Joe Brody is anyone to go by – is that he's a hit man who works for anyone, that is to say anyone who comes up with the right target for the right price. Brody says the KGB have used him over the past two years. If Thurkettle was on his way to see our friends in Normannenstrasse, he'd fly into Schönefeld.'

'You mean he's targeting someone here in the West?' Frank screwed his face up. 'I can't put a tail on him. I don't know where he's gone, and even if I did know I simply haven't got the resources.'

' West Berlin isn't on the way to anywhere,' I said. 'No one conies here en route to anywhere; they come here and go back again.'

'You're right. Perhaps I should send London a reminder.' He used his clenched fist to brush up the ends of his moustache. To the casual observer it looked as if he was giving himself two quick punches on the nose: perhaps that's what he thought London was likely to give him if he persisted. 'I'll leave it for the weekend; they might respond again.'

Good old Frank: never hesitate to do nothing. 'Phone the old man,' I suggested.

'The D-G? He hates being disturbed at home.' He scratched his cheek and said, 'No, I'll leave it for the time being. But I'm disturbed by what you told me, Bernard.'

I realized that my description of Thurkettle's activities had put Frank into a difficult position. Until talking with me he still had the chance to plead ignorance of anything concerning the man or the danger that he might present to Allied personnel here. I wondered if I should suggest that we both forget what I'd said but Frank could be very formal at tunes. Despite the friendship that went back to my childhood – or even because of it – he might consider such a suggestion treasonable and insulting. I decided not to take a chance on it.

'One thing I still haven't got clear, Frank,' I said. He raised an eyebrow. 'You sent Teacher to get me, and had me sit in on Larry Bower and the old apparatchik. Why?'

Frank smiled. 'Didn't Larry explain that?'

'No,' I said. 'Larry didn't explain anything.'

'I thought it might be something that would interest you. I remembered that you were handling Stinnes at one time.'

'Why not simply show me the transcript?'

'Of the debriefing?' Pursed lips and a nod, as if this was a novel and most interesting suggestion. 'We could have done that; yes.'

'Would you like to hear what I think?' I said.

'Of course I would,' said Frank with that suppressed irony with which a doting parent might indulge a precocious child. 'Tell me.'

'I kept thinking about it. I wondered why you would give me a close look at a still active agent. That's not the way the training manual says it's done.'

'I don't always go by the training manual,' said Frank.

'You are not contrary or perverse, Frank,' I said. 'What you do, you do with a purpose.'

'What's eating you, Bernard?'

'You didn't invite me to that safe house in Charlottenburg to hear the debriefing and see Valeri,' I said. 'You brought me over there so that Valeri could see me. See me close up!'

'Werner is a German national

'Yes, killed.' Frank looked again at the map, as if searching for something, but I think he was trying to avoid my eyes. 'Jeremy has the gun for that purpose.'

'Poor bloody agent,' I said.

'All concerned are aware of what's at stake,' said Frank stiffly. 'Including the agent.'

Frank turned and looked at me now. His blunt-ended moustache was completely grey these days, prank was too old to be involved with Operations. Too old, too squeamish, too weary, too good-hearted. Whatever it was, the strain on him showed in his face.

'It's all right, sir,' said the ever-helpful Teacher. 'We'll do whatever has to be done.'

Teacher's face was lined too, but Teacher was not old nor weary. Teacher was a tough little bastard in a way that I'd not recognized before. They'd chosen him well for this job.

Frank seemed not to hear Teacher. It was as if it were just me and Frank in the room. 'Okay, Bernard?' he just said softly. I looked Frank in the eyes and I knew, beyond any shadow of a doubt, that it was Fiona who was going to be picked up on the Autobahn. It was Fiona who knew what might have to be done to prevent her being interrogated by the professional torturers at Normannenstrasse. And Teacher was there in case I hesitated when it was time to pull the trigger.

'Yes, Frank,' I said. 'It's okay.'

On the Sunday evening there was a big party at Lisl's. The printed invitations said it was to celebrate the opening of the newly refurbished premises. On this pretext Werner had obtained the support of a number of his suppliers, and the invitations, like the paper napkins and some of the other objects in evidence, bore the trademarks of breweries and distillers.

Now that it was almost summer, and the evenings had lengthened, Werner's plan was to hold the party in a huge tent he'd had erected in the courtyard at the back of the hotel. But all afternoon the sky had darkened and by evening there was torrential rain falling from an endless overcast. Only the most intrepid guests ventured into the chilly tent, and the inauguration was celebrated indoors.

But it was something more than the official reopening of the hotel. And it was Frank's presence at the party at Lisl's on Sunday evening that told me that he felt the same way. Frank was past retirement, soon he would be gone. Looking back on it afterwards, I saw that he regarded it as his very own gala finale. Frank had never shared my love for Lisl, and despite all evidence to the contrary, he persisted in blaming Werner for that old 'Baader Meinhof fiasco for which Frank had taken a share of criticism. But even Frank knew that List's was the only place in Berlin to celebrate, and having decided that, he was at his most ebullient and charming. He even wore fancy costume: the Duke of Wellington!

'It's the end of an era,' said Lisl. We were sitting in her little study. This was the room in which Lisl spent so much of her life now that walking had become so painful for her. Here she had breakfast, and played bridge and looked at the account books and gave favoured residents a measured glass of sherry when they came to pay their bills. On the wall there was a picture of Kaiser Wilhelm, on the mantelpiece a hideous ormolu clock, and around the table where she took breakfast four carved Venetian-style figure-of-eight dining chairs, all that remained of her parents' grand dining room.

Now she never sat in her beloved chairs; she was in a functional steel wheelchair that she could manoeuvre at such high speed that Werner had fixed a small bulbhorn to it.

The noise of the party came loudly through the tightly closed door. I don't know whose idea it was to use Lisl's wind-up gramophone and her collection of ancient 78s to provide the music, but it had been hailed as the ultimate in chic, and now Marlene was purring 'Falling in Love Again' against a honky-tonk piano for what must have been the fifth consecutive time. Werner had predicted that it wouldn't be loud enough but it was loud enough.

Even Lisl had sought refuge from the dedicated and unrelenting playfulness that Berliners bring to their parties. Open on the floor there was a very old suitcase that had belonged to my father. It dated from the days before designer labels, when such things were properly made. The outside was pale green canvas with leather for the handle, the binding and the corners. The lining was calico. Inside it there were his papers: bills, accounts, newspaper clippings, a couple of diaries, a silk scarf, even the British army uniform tunic that he so seldom wore. I was rummaging through it while Lisl sat in her wheelchair, sipped her sherry and watched me. 'Even his gun,' she said. 'Be careful with it, Bernd. I hate guns.'