From the height where the dive had started it would have taken roughly sixty seconds for the sound to reach the ground: by that amount I was listening to the past; but as the dive went on the distance closed and sound was catching up on vision. It was now uncomfortable on the ear-drums. I couldn't estimate speed because the plane was almost head-on to the binoculars. In a vertical dive there wouldn't be any power on but the Striker was built to stand 1500 knots and it could reach that speed by gravity. All I knew was that this scream was the sound of something going very fast.

Time started telescoping now and I was worrying. The plane was big enough at this stage to see without the binoculars and I dropped them and cupped my hands to block out the glare and watch the thing coming on at the ground without any sign of pulling out or any sign of being able to pull out. The shrilling was so bad now that it was difficult to go on thinking rationally because the primitive brain was telling me to get up and run somewhere safe while the modern brain was working out a few figures: the plane was now below half its attainable ceiling and coming on at something like its peak attainable airspeed which put it at a mile for every four seconds and that gave me fifteen seconds to get out and there was nowhere to go.

Then the whole sky went dark as the plane's shadow passed over me and the noise was so loud that I was on my feet and running by the time it hit the ground a hundred yards away. The impact was explosive and comparable to a medium-charge conventional bomb detonating just below ground level in soft conditions. Earth began falling on me soon after the shock-wave had passed and there was a spherical cloud of chalk billowing round the crater the plane had made. I was running into it and through it until the fore-brain took over and stopped me. There was no need to run any more.

Then I began moving through the Weird white light, lurching against my own shadow that the sun was throwing against the chalk. I could have believed I wasn't alone. It took a minute to reach the edge of the cloud and I was choking a bit. Mixed with the damp-cellar smell of the chalk was the sharpness of molten metal and kerosene. The flame-wave followed me and I had to start running again until I was clear.

The wailing sound got on my nerves and I had to stop and identify it: the birds following the tractor had flown to a group of elms and were still calling in fright at the explosion. The man had left his tractor and was lumbering towards the cloud of burning kerosene as if there were something he could do.

I found the binoculars and went back to the car, turning it towards Westheim. On the way there I realized something. Parkis had known.

Most of the post office staff were still outside and people were telling them what had made the noise, but one man was behind the counter and I gave him the number and hung about for ten minutes until the connection was made. London would get it by the overt intelligence sources in a few hours but they wanted it quicker than that or they wouldn't have sent me here as an observer. They hadn't warned me to use speech-code when reporting so I compromised and just said: 'The fly fell down.'

People with Pekingese grow to look like Pekingese.

The Bureau doesn't officially exist, so everyone there has grown to look anonymous. They are flesh and blood but you never quite know whose flesh or whose blood they consist of today: you get the odd feeling that during the night there was enacted an unspeakable rite involving flesh-eating and blood-letting by some refined form of extrasensory transference and that the A-positive you were talking to yesterday is now Rhesus-negative.

The permanent staff at the Bureau have another thing in common. Whenever I show up there they look as if someone has left a dead rat on their desk. They looked like that when I flew in from West Germany and asked to see Parkis. It took nearly an hour to get into his room: he is very high in the Whitehall 9 Echelon and his room is behind what amounts to a series of distorting mirrors constructed on the principle of the Chinese Box, the idea being that halfway through the system you give up and ask for the street.

But I wanted to see Parkis about the fly so I kicked up a bit of fuss and they finally got the message and sent me into his room. This is the room with the smell of polish and the Lowry. It's a good picture but it has associations for me. I was standing under this picture the day Parkis invited Swanner to resign. Swanner had mucked up a mission and three of us were present when Parkis stood there with his hands clasped in front of him and his small feet together and broke the man up while we listened. We didn't like it. Parkis should have told us to get out first. I was standing under this picture the day when Lazlo put a pill in his mouth before we could get to him. That was all right: he was finished and knew it and did the sensible thing and at least he died in civilized surroundings instead of where they would have put him if we'd thrown him back over the frontier. But he was on the floor and already turning green when Parkis told us to 'take it away and get it buried'. We didn't like that either: it was said for effect.

The worst thing about Parkis is that he is the most anonymous-looking of all at the Bureau. His face is so ordinary that it could only be a mask and his eyes are like holes in it because they are colourless. He stands so still that you feel you could walk up to him and go on walking right through him and not notice anything but a slight chill on the skin. But you'd come out Rhesus-negative.

I was standing under the picture now. It's the only place to stand, because of the disposition of the desk and the filing cabinets and the briefing table. It may be arranged like that because when Parkis talks to you he looks at the picture most of the time, just above your head, to remind you that you don't exist any more than he does, any more than the Bureau does.

He had got up when I came in. He stood in front of me with his hands clasped together, looking at the Lowry.

'How was Munich?'

'All right.'

They'd pulled me out of Munich to watch the fly.

'Did anything happen there?'

'Munich?'

'Yes.'

'I sent in my report.'

'Ah.' It sounded as if he hadn't seen it but I knew he had. They would have pulled me out before long anyway for lack of 'positive lead-in data', by which they mean the smell of anything fishy.

'I expect you'll be going to Paris, will you?'

'No one mentioned leave,' I said.

'Waring is due back.' He looked at me instead of the picture.

'There was nothing doing in Munich. That was as good as leave.'

'Not quite Paris, is it?'

'This aeroplane,' I said.

'It isn't for you.'

'Why not?'

'You're a shadow executive.'

He turned away.

'Why was I sent there?'

To observe.'

'Well I did.'

'But you didn't observe anything. It just fell down, so you said. We wanted to know why.' He was staring out of the window at the winter sky.

The portfolio on his desk had a word on the cover.

'That's all I saw. You read my report. It just came down like a ton of bricks.'

The word on the cover was Striker.

'Quite.'

'Look, is it because I mucked up the Bangkok thing?'

'I don't think you mucked it up, did you?' He turned round again and I could watch his face, the mask with the colourless holes. 'We're giving this one to Waring.'

'Why him? He doesn't know anything about aeroplanes. He doesn't know which end the flint goes in.'

Parkis stood very still. 'It's not really about aeroplanes.'

I was getting fed up. 'You send me out to a precise map reference just in time to fetch a Striker SK-6 on top of my head and now you say it's nothing to do with aeroplanes.'