'Of course,' I said, and tried to make it sound as if I knew what she was talking about. The truth was, I wished like hell that I had a few more people in my life wanting to take orders instead of giving them.

'Have some more coffee,' she said sweetly. 'But then I must insist that you tell me what this is all about. Mysterious strangers can outstay their welcome too, you know.'

'You've been very patient with me, Mrs Volkmann and I appreciate that. My purpose in seeking you out was to tell you, unofficially, that under the circumstances my masters in London feel that you must be positively vetted.'

'A security check?'

'Yes, Mrs Volkmann. There will have to be a security check. You will be positively vetted.'

'This has already been done when I first married Werner.'

'Ah, well, this will be quite different. As you know, Frank Harrington is an important British official. We will have to make this what we call a Category Double X clearance. We hope you will understand why this has to be done and cooperate with the people assigned to the job.'

'I don't understand. Can't Frank arrange it?'

'If you pause a moment, Mrs Volkmann, you'll see how important it is that Frank doesn't know about it.'

'Frank will not be told?'

'Let Frank keep his private life secret. Frank's gone to a lot of trouble to do all this…' I waved a hand vaguely in the air. 'How would he feel if young men from his own office had to compile reports on where you went, who you saw, how much you have in the bank? And how will he feel if he has to read reports about some old relationships that you have half forgotten and can only cause him pain?'

She inhaled on her cigarette, and looked at me through half-closed eyes. 'Are you telling me that this is the sort of thing that your investigators will pry into?'

'You're a woman of the world, Mrs Volkmann. You've obviously guessed that the investigation has already started. None of the agents assigned to you has actually reported to me yet, but you must have spotted my men following you during the past three or four weeks. We don't assign our most experienced people to these vetting jobs of course, and I'm not surprised that you realized what is in progress.'

I waited for her reaction, but she sat well back on the sofa and looked me in the eyes. She smoked but said nothing.

I said, 'I should have come to tell you about all this a month ago, but so much work piled up on my desk that I found it impossible to get away.'

'You bastard,' she said. There was no smile this time. I had the feeling that this was the real Zena Volkmann.

'I'm just carrying out my orders, Mrs Volkmann,' I said.

'So was Eichmann,' she said bitterly.

'Yes, well you know more about German history than I do, Mrs Volkmann, so I'll have to take your word for that.'

I gulped down the last of my coffee and got to my feet. She didn't move but she watched me all the time.

'I won't go out the back way if you don't mind,' I said. 'I don't want to disturb the dogs.'

'You're frightened that the dogs will tear you to pieces,' she said.

'Well, that's another reason,' I admitted. 'No need to show me to the door.'

'Frank will get you kicked out of the service for this,' she promised.

I stopped. 'I wouldn't mention any of this to Frank if I were you, Mrs Volkmann,' I said. 'This is a London decision, a decision made by Frank's friends. If it all became official, Frank would have to face a board of inquiry. He'd have a lot of explaining to do. The chances are he'd lose his job and his pension too. If that happened, Frank's friends might feel it was all your fault. And Frank has friends in Bonn as well as London – very loyal friends.'

'Get out!'

'Unless you've something to hide, they'll be no problem,' I said.

'Get out before I set the dogs on you.'

I went back to the car and waited. I decided to give it an hour and a half and see whether my hastily improvised story provoked any comings and goings. At that time on a Saturday afternoon there was not much traffic; something should happen soon, I told myself.

I could see the house from the driver's seat of the car. It was an hour and a quarter later that she came out carrying a big Gucci suitcase and an overnight bag. She was dressed in a leopard-skin coat with a matching hat. Real skin, of course. She was not the sort of lady who worried too much about leopards. The car arrived even before she closed the garden gate. She got into the front seat beside the driver and the car moved off immediately. I reached forward to turn the ignition key, but I had already recognized the car she climbed into. It was Werner's Audi and Werner was driving it. She was talking to him with much waving of the hands as the car passed mine. I ducked down out of sight but they were too involved in their discussion to notice me. So much for all her lies about Werner. And so much for all Werner's stories about her.

No point in chasing after them. Werner would be sure to see me if I tried to follow. In any case, Berlin is well covered. The security officers at the road checkpoints, the airport and the crossing places would be able to tell me where they went.

I went back to the house. I opened the pantry window with a wire coat hanger that I found in my car. She had left hurriedly. The coloured plastic bowls were piled up unwashed in the pantry sink. Frank wouldn't like that. In fact, he wouldn't like my putting his lady to flight if he found out what I'd done. There were lots of things he wouldn't like.

There was a note on the phone. It said simply that Zena had gone away for a few days because of a family crisis and she'd phone him at the office next week. It went on to say that a neighbour would feed the dogs, and would Frank leave one hundred marks on the hall table.

Whatever kind of racket Werner was in, it looked as if Zena was in it too. I wondered if it depended upon getting information from Frank, and what sort of information it was.

From Bret Rensselaer's top-floor office there was a view westwards that could make you think London was all greenery. The treetops of St James's Park, Green Park and the gardens of Buckingham Palace, and beyond that Hyde Park made a continuous woolly blanket. Now it was all sinking into the grey mist that swallowed London early on such afternoons. The sky overhead was dark, but some final glimmers of sunlight broke through, making streaky patterns on the emerald rectangles that were the squares of Belgravia.

Despite the darkness of the rain clouds, Rensselaer had not yet switched on the room lights. The thin illumination from the windows became razor-shape reflections in all the chromium fittings and made the glass-top desk shimmer like steel. And the same sort of metallic light was reflected up into Rensselaer 's face, so that he looked more cadaverous than ever.

Dicky Cruyer was hovering over the boss, but moving around enough to see his face and be ready with an appropriate answer. Cruyer was well aware of his role; he was there whenever Rensselaer wanted witness, hatchet man, vociferous supporter or silent audience. But Cruyer was not a mere acolyte; he was a man who knew that 'to everything there is a season… a time to embrace and a time to refrain from embracing'. In other words, Cruyer knew exactly when to argue with the boss. And that was something I never did right. I didn't even know when to argue with my wife.

'You didn't tell Frank that it was all genuine material?' Cruyer asked me for the third time in thirty minutes.

'Frank doesn't give a damn whether it's genuine or not,' I said. They both looked at me with pained shock. 'As long as it didn't come dribbling out of his Berlin office.'