'No,' I said. Bret could always find a way of putting his opponents in the wrong.

Fiona said nothing. Her contribution to the talking was minimal and yet she was not uncooperative: she was like a sleep-walker. She knew her sister was dead – Bret had told her – but she avoided mention of Tessa. It was as if Tessa had never been there, and Bret left it like that. There were a lot of things that Fiona would not talk about, she seldom even mentioned the children. I didn't envy Bret his task.

Bret looked at his watch. 'Well, let's move on to a few easier questions. We'll get some of those rare roast beef sandwiches sent in, and break early. How about that?'

The sandwiches were lousy too.

A couple of days later we had a visitor. James Prettyman was an Americanized Englishman who used to work alongside me. Since then London Central had sent him to Washington in some deep cover plan that enabled him to do things for them at arm's length. Atone time we'd been close friends. Now I wasn't so sure, although I suppose I owed him a favour or two.

Jim was in his early thirties. He had the wiry form and presence of mind that are associated with the pushier type of door-to-door salesmen. His complexion was pale and bloodless. His head was domelike and he was losing his silky hair but sometimes a strand of it fell across his eyes. I think he was glad to see it.

It was early in the morning when he arrived. He was wearing a blue striped suit, the lightweight cotton you need in Washington DC at this sweaty time of the year. There was a paisley silk square in the top pocket and the trousers were very rumpled, as if he'd been strapped in to his seat for a few hours.

'Good to see you, Bernie,' he said and gave me a sincere handshake and fixed me with his eyes, in that way that Americans do when they are trying to recall your name. I'm sitting in.' He looked at his watch. 'Later this morning. You, me and Bret: okay?'

'Good,' I said, uncertain of what was expected of me. I thought he must have come to talk with Fiona but she was taking breakfast in bed having been given a morning of 'free activity'.

Bret Rensselaer went into secret session with Jim Prettyman and I was summoned to join them at ten o'clock. The remains of their breakfast were still distributed around the room. Bret couldn't think without striding round the room so there were plates of half-eaten corn muffins, cups and unfinished glasses of orange juice on every side. I poured myself coffee from the vacuum jug and sat down. I reached for the cream jug but when I poured from it only a drip or two remained.

Bret Rensselaer said, 'Jim would like to hear your version of what happened.'

I looked at Bret and he added, 'On the Autobahn.'

'Oh,' I said. 'On the Autobahn.'

'Who was this man on the motor cycle?' said Prettyman.

'No one seems to know,' I said.

'I told Jim you had theories,' said Bret. 'And I told him you wouldn't open up.'

Jim said, 'Off the record, Bernie.'

'It was a dark night, Jim,' I said.

He leaned forward and switched off the tape recorder and said, 'Off the record.'

'Oh, that kind of off the record,' I said. I drank some coffee. It was cold. 'I think your vacuum flask is on the blink,' I said. 'Yes, well… He had an American accent.'

'They've all got American accents,' said Bret. 'It's the teaching machines.'

'So I hear,' I said.

'Did you recognize the voice?' said Prettyman.

'Are you putting me on?' I asked. 'Do we have to go through with this nonsense?'

'Who was it?'

'Jesus, Jim! You know who it was. It was a thug named Thurkettle, a renegade American. A hit man the Department brought in to make sure Tessa Kosinski was blown away.'

'Why you dumb…' started Bret, but Prettyman waved a hand that silenced him.

'Tell me more,' said Prettyman. 'Why would the Department want to kill Fiona's sister?' It was casually put, but in his voice there was that specially kindly tone with which psychiatrists coax maniacs.

'The car burned,' I said. Tessa Kosinski's remains – no more than a few bone fragments and ashes – will be identified as her sister Fiona. Fiona is hidden here: Moscow won't know that she is alive and well and spilling everything to you guys.'

'You're forgetting the teeth,' said Bret. They are sure to find some jawbone. Fiona had dentistry – a crown and a filling – while she was over there in East Berlin.' If anything was needed to convince me that my theory was right, it was Bret's remarkable knowledge of Fiona's dental chart.

Prettyman looked at Bret and then at me and then sneaked a quick look at his wristwatch.

'I'm forgetting nothing,' I said. 'Let's suppose a skull, sufficiently like Fiona's, was fitted with dental work that exactly matched hers. That would have been put into the car.'

'Two women's skulls in the car?'

'That's why you need a madman like Thurkettle. Hacking a head from a body is covered by his all-inclusive fee.'

'Thurkettle is the one who wasted the CIA man in Salzburg,' said Prettyman, as if remembering the name from something in the dim and distant past. Then he said, 'It would need a lot of planning… a lot of cooperation. Who would put him in position and so on?'

'There was drug trafficking: officials on both sides. A scapegoat was needed. All concerned were desperate to close the file. That spot, with the construction work on the highway, would provide a chance to bury any inconvenient evidence.'

'Where did you get all this?' said Prettyman.

I said, 'It's the only feasible explanation.'

'You'll have to do better than that, Bernie,' said Prettyman in a voice that seemed truly friendly. 'I'll listen to anything you have to say. I learned what I know from you: all of it. But you'll have to do a rewrite for that cockeyed script.'

'So what in hell was Tessa doing there?'

It was Bret's turn to speak. 'Isn't that a question for you to answer, Bernard? You took her there with you. Remember?'

'Will you go and see Gloria?' I asked Prettyman on a sudden and desperate impulse. Tell the children I'm well and that I love them?'

Bret said nothing.

Prettyman calmly said, 'There's not much chance of me getting a trip to London anytime in the foreseeable future, Bernie.'

I drank my tepid black coffee and didn't answer.

'I'll be back,' Prettyman told me like a dutiful son visiting a difficult octogenarian. 'But I have to be at Camarillo Municipal Airport by two. Next month maybe… Good to see you, Bernie. Really good! I mean that sincerely.'

'Get stuffed!' I said.

Prettyman looked at Bret. Bret responded with a tiny shrug as he was showing Prettyman out. I remained where I was but I could hear them in the next room. As they parted I heard Prettyman say, 'What a tragedy. Both of them.'

I heard Bret reply, 'It's not too late. Let's see what happens.'

It was a week afterwards that I learned that Camarillo Municipal Airport used to be a fully equipped US Air Force operational base and that the runways are still in good order. So when Prettyman went there he hopped back into the supersonic military jet that had brought him, and he was in Washington for happy hour. I suppose it was something that Fiona had said to Bret and Washington had to be told double quick.

We'd been at the house for over a month before Fiona began to open up to me. Even then what she said was fairly banal stuff about her day-today work in Berlin, but it was a start. Then each evening it became routine for us to talk for half an hour or so. Sometimes we'd talk over a drink in our sitting room, and sometimes we'd take a walk around the perimeter fence. Then one evening Fiona almost trod upon a big grey rattlesnake, and after that we kept to the paths and the terrace. It was a big property, and high enough so that on a pitch-black night like this the California coastline shone like a diamond necklace laid out all the way to Los Angeles.