She was not an explorer nor an experimenter; Fiona's brain was at its best when evaluating material and planning its use. It was a capacity that provided her with an excellent chance to judge her own potential as a field agent. Secrecy she had in abundance, but she didn't have many of the qualities she saw in Bernard. She didn't have his street-wise skill at fast thinking and fast moving. Fiona could be mean, stubborn and cold-hearted, but these for her were long-term emotions: Bernard had that mysterious masculine ability to switch on cold-blooded hostility at a moment's notice and switch it off a split-second later. She pulled the hat down over her ears. The sky blackened and the rain was getting worse. She must get back in time to bathe and change for dinner. Saturday night dinners were dress-up affairs when you stayed with Uncle Silas. She would have to do something with her hair and borrow the iron to smooth her dress. Tessa and the other women would have been preparing themselves all afternoon. She looked at her watch and at the route back. Even the friendly rolling Cotswolds could become hostile when darkness fell.

'You looked very glamorous last night, my dear,' said Uncle Silas.

'Thank you, Silas. But to tell you the truth I can't keep up with the smart chatter these days.'

'And why should you want to? I like you when you are serious: it suits you.'

'Does it?'

'AH beautiful women look their best when sad. It's different for men. Handsome men can be a little merry but jolly women look like hockey captains. Could any man fall in love with a female comic?'

'You talk such rubbish, Silas.'

'Was it that dreadful architect's prattle that pissed you off?'

'No. It was a wonderful evening.'

'Swimming pools and kitchens; I don't think he can talk about anything else. I had to invite him though, he's the only blighter who knows how to repair my boiler.'

He laughed. It was some complicated joke that only he appreciated. He'd grown accustomed to his own company and remarks like this were solely for his own satisfaction. They were sitting in the 'music room', a tiny study where Silas Gaunt had installed his hi-fi and his collection of opera recordings. There was a log fire burning and Silas was smoking a large Havana cigar. He was dressed in a magnificent knitted cardigan. It had an intricate Fair Isle pattern and was coming unravelled faster than Mrs Porter could repair it, so that woollen threads trailed from his elbows and cuffs.

'Now tell me what's troubling you, Fiona.' From the next room there was the measured and intricate sound of a piano: it was Bret playing 'Night and Day'.

Fiona told Silas about Tessa's exchanges with Giles Trent, and when she had finished he went and looked out of the window. The gravel drive made a loop around the front lawn where three majestic elms framed the house. Tessa's racing-green Rolls-Royce was parked outside the window. 'I don't know how your sister manages that car,' he said. 'Does her husband know she uses it when he's away?'

'Don't be such a pig. Of course he does.'

He looked at her. Then it sounds as if we've got an orange file on our hands, Fiona.'

'Yes, it does.' An orange file meant an official inquiry.

'Giles Trent: the treacherous swine. Why do these people do it?' She didn't answer. 'What would you have done if Tessa had put this to you but without the special situation that you are in?'

Without hesitation Fiona said, 'I'd have taken it to Internal Security. The Command Rules spell it out.'

'Of course you would.' He scratched his head. 'Well we can't have the IS people in on this one, can we?' Another pause. 'You wouldn't have mentioned it to your husband first?'

'No.'

'You seem very sure of that, Fiona.'

'It would be the same for him, wouldn't it?'

'I'm not sure it would.'

'Uncle Silas! Why?'

He turned and looked at her. 'How can I put it to you… You and I belong to a social class obsessed by the notion of conduct. At our best public schools, we have always taught young men that "service" is the highest calling, and I'm proud that it should be so. Service to God, service to our sovereign, service to our country.'

'You're not saying that because Bernard wasn't at public school – '

He held up a hand to stop her. 'Hear me out, Fiona. We all respect your husband. Me more than anyone, you know that. I cherish him. He's the only one out there who knows what it's like to be in the firing line. I'm simply saying that Bernard's background, the boys he grew up with and his family, have another priority. For them – and who is to say they are in error? – loyalty to the family comes before everything. I really do mean before everything. I know, I've spent my life commanding men. If you don't understand that aspect of your husband's psyche you might get into a lot of trouble, my dear.'

'Working-class boys, you mean?'

'Yes. I'm not frightened to say working-class. I'm too old to care about taboos of that sort.'

'Are you saying that if Tessa had taken her problem to Bernard he would have hushed it up?'

'Why don't we put it to the test? Sit your husband down next week and have Tessa tell him her story.'

'And what do you think he'll do?'

'More to the point, what do you think he'll do?' said Silas.

'I can't see that any benefit could come of such speculation,' said Fiona. Silas laughed at the evasion, Fiona was irritated and said, 'You are the one making the allegations, Silas.'

'Now, now, Fiona. You know I'm doing nothing of the kind. Put it to Bernard, and he'll find some ingenious solution that will keep you and Tessa out of it.' He smiled artfully. The word ingenious implied Bernard's flagrant disregard, if not to say contempt, for the rule book, and that was something Silas shared with him.

'Bernard has a lot on his mind right now,' said Fiona.

'Make sure you ask him to keep Tessa out of it.' He found a loose thread, tugged it off and dropped it carefully into the fire.

'How?' said Fiona.

'I don't know how. Ask him.' He smoked his cigar. 'A far more important thing for the moment is that Giles Trent has obviously been used to monitor everything you've been telling them.' He blew smoke, making sure it went towards the fire. Whenever Mrs Porter smelled cigar smoke she nagged him: the doctor had told him not to smoke. 'You must have thought about that. Any worries there?'

'Nothing that I can think of.'

'No, I think not. We've kept you very very secret and given them only strictly kosher material. Whatever Trent has been reporting to them, his reports will have only increased your status with Moscow.'

'I hope so.'

'Cheer up, Fiona. Everything is going beautifully. This will suit our book. In fact I'll get permission for you to visit the Data Centre again. That should make your masters prick their ears, what?'

'Will you tell Bret about Tessa?' She didn't want to face Bret with it herself: it would become an interrogation.

'Let's tell him now.' Having hidden his cigar in the fireplace he pressed a bellpush. Seeing the look of alarm on Fiona's face he said, 'Trust your Uncle Silas.' 'Night and Day' continued in the next room.

When Mrs Porter put her head round the door he said, 'Ask Mr Rensselaer if he can spare a moment. I think I heard him playing the piano.'

'Yes, sir. I'll tell him right away.'

When Bret came – eyebrows raised at seeing Fiona with Silas in what was obviously some kind of discourse – Silas said, 'It's good to hear the piano again, Bret. I keep it tuned but nowadays no one plays.' Bret nodded without replying. Silas said, 'Bret, we seem to be having another problem with our playmates.'

Bret looked from one to the other of them and got the idea instantly. 'This is getting to be a habit, Fiona,' he said. Bret was huffed that she'd taken her story to Silas Gaunt and didn't disguise his feelings.