'Like all those infuriatingly incompatible video-recorders.'

'Exactly. But you'd think the computer firms would have more sense. They may hang on to their own customers by force, but they're sure as Hades not going to persuade anyone else to switch.'

'Thanks anyway,' I said.

'You're welcome.' He hesitated. 'Do you actually have a tape that you want to use?'

'Yes.' I fished in my pocket and produced Oklahoma. This one and two others. Don't be misled by the packaging, it's got computer noise all right on the tape.'

'Were they recorded by an expert or an amateur?'

'An expert. Does it make any difference?'

'Sometimes.'

I explained about Peter making the tapes for a client who had a Grantley, and I added that the customer wouldn't let Peter try out the programs on the machine they were designed to run on.

'Oh, really?' Ted Pitts seemed happy with the news. 'In that case, if he was a conscientious and careful chap, it's just possible that he recorded the machine language itself on the first of the tapes. TOMs can be very touchy. He might have thought it would be safer.'

'You've lost me,' I said. 'What are TOMs?'

'Computers.' He grinned. 'Stands for Totally Obedient Moron.'

'You've made a joke,' I said disbelievingly.

'Not mine, though.'

'So why should it be safer?'

He looked at me reproachfully, 'I thought you knew more about computers than you appear to.'

'It's ten years at least since I knew more. I've forgotten and they've changed.'

'It would be safer,' he said patiently, 'because if the client rang up and complained that the program wouldn't run, your friend could tell them how to stuff into their computer a brand-new version of its own language, and then your friend's programs would run from that. Mind you,' he added judiciously, 'you'd use up an awful lot of computer space putting the language in. You might not have much room for the actual programs.'

He looked at my expression, and sighed.

'OK,' he said. 'Suppose a Grantley has a 32K store, which is a pretty normal size. That means it has about forty-nine thousand store-slots, of which probably the first seventeen thousand are used in providing the right circuits to function as Basic. That would leave you about thirty-two thousand store-slots for punching in your programs. Right?'

I nodded. 'I'll take it on trust.'

'But then if you feed in the language all over again it would take another seventeen thousand store-slots, which would leave you with under fifteen thousand store-slots to work with. And as you need one store-slot for every letter you type, and one for every number, and one for every space, and comma, and bracket, you wouldn't be able to do a great deal before all the store-slots were used and the whole thing was full up. And at that point the computer would stop working.' He smiled. 'So many people think computers are bottomless pits. They're more like bean bags. Once they're full you have to empty the beans out before you can start to fill them again.'

'Is that what you teach the kids?'

He looked slightly confused. 'Er… yes. Same words. One gets into a rut.'

The bell rang for afternoon registration and he stretched out his hand for the tape. 'I could try that,' he said, 'if you like.'

'Yes. If it isn't an awful bother.'

He shook his head encouragingly, and I gave him The King and I and West Side Story for good measure.

'Can't promise it will be today,' he said. 'I've got classes all afternoon and Jenkins wants to see me at four.' He grimaced. 'Jenkins. Why can't we call him Ralph and be done with it?'

'There's no hurry,' I said, 'with the tapes.'

Donna got her probation.

Sarah reported, again sounding tired, that even the baby's mother had quietened down because of Peter being killed, and Donna had gently wept in court, and even some of the policemen had been fatherly.

'How is she?' I said.

'Miserable. It's just hitting her, I think, that Peter's really gone.' Her voice sounded sisterly, motherly, protective.

'No more suicide?' I asked.

'I don't think so, but the poor darling is so vulnerable. So easily hurt. She says its like living without skin.'

'Have you enough money?' I said.

'That's just like you!' she exclaimed. 'Always so damned practical.'

'But…'

'I've got my bank card.'

I hadn't wanted to wallow too long in Donna's emotions and it had irritated her. We both knew it. We knew each other too well.

'Don't let her wear you out,' I said.

Her voice came back, still sharp, 'I'm perfectly all right. There's no question of wearing me out. I'm staying here for a week or two longer at least. Until after the inquest and the funeral. And after that, if Donna needs me. I've told my boss, and he understands.'

I wondered fleetingly whether I might not become too fond of living alone if she were away a whole month. I said, 'I'd like to be there at the funeral.'

'Yes. Well, I'll let you know.'

I got a tart and untender goodnight: but then my own to her hadn't been loving. We wouldn't be able to go on, I thought, if ever the politeness crumbled.

The building had long been uninhabited, and we were only a short step from demolition.

On Saturday I put the Mausers and the Enfield No. 4 in the car and drove to Bisley and let off a lot of bullets over the Surrey ranges.

During the past few months, my visits there had become less constant, partly of course because there was no delight during the winter in pressing one's stomach to the cold earth, but mostly because my intense love of the sport seemed to be waning.

I had been a member of the British rifle team for several years but now never wore any of the badges to prove it. I kept quiet in the bar after shooting and listened to others analyse their performances and spill the excitement out of their systems. I didn't like talking of my own scores, present or past.

A few years back, I had taken the sideways jump of entering for the Olympics, which was a competition for individuals and quite different from my normal pursuits. Even the guns were different (at that time all small bore) and all the distances the same (300 metres). It was a world dominated by the Swiss, but I had shot luckily and well in the event and had finished high for a Briton in the placings, and it had been marvellous. The day of a lifetime; but it had faded into memory, grown fuzzy with time passing.

In the British team, which competed mostly against the old Commonwealth countries and often won, one shot 7.62 mm guns at varying distances – 300, 500, 600, 900 and 1,000 yards. I had always taken immense delight in accuracy, in judging wind velocity and air temperature and getting the climatic variables exactly right. But now, both internally and externally, the point of such skill was fading.

The smooth elegant Mausers that I cherished were already within sight of being obsolete. Only long-distance assassins, these days, seemed to need totally accurate rifles, and they used telescopic sights, which were banned and anathema to target shooters. Modern armies tended to spray out bullets regardless. None of the army rifles shot absolutely straight and in addition, every advance in effective killing-power was a loss to aesthetics. The present standard issue self-loading rifle, with its gas-powered feed of twenty bullets per magazine and its capability of continuous fire, was already a knobby untidy affair with half of it made of plastic for lightness. On the horizon was a rifle without a stock, unambiguously designed to be shot from waist level if necessary with no real pretence at precise aim: a rifle with infra-red sights for night use, all angular protuberances. And beyond cordite and lead, what? Neutron missiles fired from ground launchers which would halt an invading tank army literally in its tracks. A new sort of battery which would make hand-held ray guns possible.