It was a phoned piece from their Bath stringer, reporting that the Cheddar caves had been closed to visitors, after the first morning tour had come up complaining of an irritant dust in the air of the lower chambers. The local Medical Officer of Health had ordered an inspection. Several of the party were in hospital with severe pulmonary symptoms.

The sub's professional instincts nudged at him, mysteriously. He frowned for a moment and then reached for the phone.

'But what's he done}' Betty Summers asked, helplessly aware that her voice was rising towards hysteria. The taller policeman (at least, Betty supposed they were policemen – she hadn't understood the identity cards they'd shown her) said soothingly: 'Your husband has done nothing, Mrs Summers. Please don't worry. Now why don't you just make yourself a cup of tea and we'll wait till he gets home?' His smile was bland, uninformative. 'You could make us one, too, if you like.' – 'But…' 'Just relax, Mrs Summers.'

She straightened a table-runner, unnecessarily, her hand shaking. She didn't believe a word of his reassurance. Phil must have been up to something – and now it was catching up on him. He'd been so preoccupied lately, not himself at all. There'd been no secrets between them in four years of marriage, till recently; the last four or five months, perhaps. Then he'd taken to brooding to himself at the oddest times – or worse, being falsely cheerful…

The phone rang and Betty jumped. She moved towards it but the second man reached it before her.

'Yes?… No, I'm afraid Mr and Mrs Summers are out this evening… Just a friend. I'll tell them you rang.'

Betty had wanted to call out but she had caught the taller man's warning eye and had been too afraid. Now she managed to ask: 'Who was it?'

'Somebody called Trevor. I'm sorry, Mrs Summers. It has to be this way.'

'Has to be what way? Why can't you tell me?'

'When your husband comes. He shouldn't be long now, should he?'

'I…'

'How about that tea? I'm sure you'd feel better.'

Perhaps he's right, she thought, a little desperately. She went to the kitchen, fighting back the tears that were trying to break out. This wouldn't do. If Phil was in trouble, he'd need her support, her help, not a weeping wife making things more difficult… If only…

She heard his key in the door, and Timmy's paws, scuffling at the woodwork as they always did. Oh, thank God… Or was it going to be even worse, now?

Betty ran to the hall but the two men were there as soon as she was. Timmy rushed in ahead of Phil, his tail wagging furiously, and stopped and growled when he saw the two strangers. Phil stopped too, questioningly.

She went to him, managing to keep her poise somehow. 'Darling – I think these gentlemen are police.'

'No,''Mr Summers. Not police. LB7.'

Phil seemed to pale a little. He said 'Oh', and shut the front door carefully. As soon as it was closed, the taller man showed Phil his identity card and then said: 'Beehive Amber, I'm afraid. Sorry about the short notice but you have an hour. I suggest you and your wife go and pack. You can explain to her now, of course.'

'Pack?' Betty croaked.

Phil put an arm round her. 'It's all right, darling. I wasn't allowed to tell even you… Oh Christ, I suppose I should have expected it, after last night… We're going away for a bit. An official job.'

'Arc you a secret agent or something?' She felt ridiculous as soon as she'd said it.

Phil sighed. 'Nothing so dramatic. Only a ventilation engineer.' He made an attempt at a laugh. 'They tell me it's a privilege to be on the list… Come on, I'll explain upstairs. Thank God I can get it off my chest at last.'

The taller man said: 'You didn't report the dog.'

'Nobody asked me,' Phil replied, looking suddenly alarmed. 'Christ, you don't have to…'

'We'll handle it.'

'Nobody asked me,' he repeated lamely.

'D'you imagine there's room for them down there?…

Go on, lad, or you'll upset Mrs Summers more.'

Phil patted Timmy's head, turning his face away. The shorter man coughed. Then Phil took his wife upstairs. The two men could hear their voices from the bedroom – hers high-pitched and bewildered, his rumbling on and on and on.

The shorter man picked up the phone and dialled a number. 'It's the only thing that gets me, when there's pets,' he complained over his shoulder. 'Why the hell don't they brief these people properly?'

Miss Angela Smith, at fifty-three the elder stateswoman of the Borough Treasurer's Department, thanked the post girl with a motherly smile. The girl had been very jittery since yesterday morning's news; the nearest earth tremor had been thirty or forty kilometres away (London had been quite unscathed) but you'd think her own house had fallen down. Oh well; not surprising when you knew the girl's neurotic mother, which Miss Smith did. As, indeed, she knew most of the borough.

Miss Smith flicked through the routine bulk of the post to see what she had to deal with herself. The perforated edge of a telex sheet caught her eye and she pulled it out; they had a way of being urgent – or if not urgent, at least from someone high enough for them to be treated as urgent.

'She read it and pursed her lips in a silent whistle, an unladylike mannerism she was well aware of but could not cure.

After the address and priority coding, the text began:

FOLLOWING TO BE TRANSFERRED TO FILE LB 0806 WEF. 26/6/04. CROWTHER 102 HOLLY MANSIONS E17. SUMMERS 43 MANOR CRESCENT E10. BERNSTEIN 97 BOUNDARY PLACE E10…'

Eighteen names and addresses. Eighteen! There had never been more than two on a File LB 0806 instruction before.

File LB 0806 matters were always handled by Miss Smith, in liaison with the Borough Treasurer himself and with no one else. She had never been told the purpose of the drill; merely given it on a sheet which was to be kept locked in her desk and reminded her of her responsibilities under the Official Secrets Act which she had been required to sign.

But Miss Smith was not a fool.

The drill itself was uncomplicated (at least when there was only one name at a time) but it was a nuisance. First, inform the accounts department that until further notice rates demands were to be sent not to the ratepayer concerned but to Miss Smith's desk. Next, contact certain named officials at the local London Electricity Board, North Thames Gas, Thames Water Authority and East Telephone Area with the same instruction. Finally (and the cloak-and-dagger solemnity of this amused Miss Smith), go to the address concerned, where a note would be -always was – pinned to the front door, telling the milkman, newsagent and anyone else concerned not to make any more deliveries till further notice. This note would always name the dairy, the newsagent and so on, and since they were all on the same sheet, none of them would have removed it. Miss Smith, however, had to remove it and then go to each of the addresses and say that as a friend of Mr So-and-so she'd been asked to settle the outstanding account. She was going to look a right Charley, this time, she thought, turning up at (for instance) one of the three major dairies in the borough and claiming to be the personal friend of half a dozen customers who'd all gone on holiday without warning on the same day.

All the accounts and the retailers' receipts, Miss Smith would then address (personally sealing the envelope) to the Home Office, Department LB7. Payment always arrived by return of post and Miss Smith's final duty would be to reimburse the London Electricity Board and the others.

Miss Smith, as has been remarked, was not a fool. Nine ratepayers of the borough had so far disappeared into File LB 0806, over the past year, and so far none of them had returned home. But these homes, she had soon become aware, were also on a Metropolitan Police list for periodic checking to make sure no harm came to them, and the police had their own keys. She guessed that the Post Office had their instructions, too.