Fiona walked from her desk waving her extended fingers at me in a manner I would have regarded as threatening had I not seen her drying her nails before. 'You had nice weather for your jaunt to Berwick House. You should have taken the Porsche.'

'Everybody expects such big tips when they see a car like that.'

'How was poor Giles?'

'Feeling sorry for himself.'

'Did he take a lethal dose or was it a cry for help?'

'A cry for help? You've been mixing with sociologists again.'

'But was it?'

'Who can tell? The bottle of tablets was empty, but it might have only had a couple of tablets in it. Thanks to his sister's quick action, he vomited before the tablets all dissolved.'

'And the doctor didn't say?'

'He was only a kid, and Dicky had obviously filled his head with dark hints about the secret service. I don't think he knew what he was doing. It was Trent 's sister who did the medical treatment. She only called in the doctor because nurses – even ex-nurses – are brainwashed to believe that they must have a doctor to nod at them while they make the decisions and do all the work.'

'Do you think he'll try again?' said Fiona. She blew on her nails.

'Not if he knows what's good for his sister. I told him I'd make sure she stood trial if he did a bolt in any direction.'

'You hate him, don't you? It's a long time since I saw you like this. I'll bet you scared the daylights out of poor Giles.'

'I doubt that very much.'

'You don't know how frightening you can be. You make all those bad jokes of yours and your face is like a block of stone. That's what made me fall for you, I suppose. You were so damned brutal.'

'Me?'

'Don't keep saying "Me?" darling. You know what a tough bastard you can be.'

'I hate the Giles Trents of this world. And if that's what you call being tough, I wish like hell there were more tough people like me. I hate the Communists and the stupid sods in this country who play their game and think they are just being "caring, sharing, wonderful people". I've seen them at close quarters. Never mind the smooth-talking little swines that come over here to visit the TUC or give talks on international friendship. I've seen them back where they come from, back where they don't have to wear the plastic smiles or hide the brass knuckles.'

'You can't run the Soviet Union as though it were the Chelsea Flower Show, darling.'

I grunted. It was her usual reply to my tirades about the KGB. Fiona, for all her talk of social justice and theories about alleviating Third World poverty, was happy to let the end justify the means when it suited her arguments. In that I could recognize the teachings of her father.

'But Trent 's not really KGB material, is he?' she said.

'They told Trent that they'd only need him for three years.'

'I suppose that was just to make it easier for him.'

' Trent believed it.'

She laughed. 'I can't imagine that Trent 's saying he believed it cut much ice with you.'

'He's not a complete idiot. I think they meant it.'

'Why? How would that make sense?'

'And his KGB contact told him to put that radio under the floorboards. That slipped out when we were talking – I'm sure that was true.'

'So what?'

'Floorboards? I'd only tell one of my agents that if I was hoping he'd get caught. You might as well take a full page in the local paper as hide a clandestine radio under the floor.'

'I'm still not following you.'

'They didn't give Trent any goodbye codes,' I said.

'What are they?'

'Numbers he can phone if he's being followed, or his home has been burgled, or he finds a security man going through his desk one morning when he arrives a bit early. They didn't even promise to get him away if anything went wrong.'

'Can you see Giles Trent living in Moscow? Really, darling!'

'KGB procedures are laid down in Moscow. They don't let any local man decide what he thinks will suit the personality of the agent he runs. You don't understand the bloody Russians. All KGB agents have goodbye codes.'

'Perhaps they have decided to change things.'

'They never change anything.'

She touched a painted nail very carefully to be sure it was dry. 'I'm ready when you are.'

'Okay.' I got to my feet and read the Chlestakov data again.

'Don't be tempted to take that computer printout from the building,' she warned. 'Security will go mad.'

'On our wedding anniversary? I wouldn't dare.' I fed the computer printout into a shredder and watched the paper worms tumble into the clear plastic bag.

'I'll buy it,' said Fiona. 'Why no goodbye codes or whatever they are?'

'I think Trent has been prepared as a scapegoat. I think they wanted us to catch him. I think they know everything we're saying to him.'

'Why?'

'The lack of any preparations for escape, the mention of three years, and then having him hide the radio – a radio he didn't need and was never trained to operate – under the floor. I think he was set up.'

'What for?'

'The only reason I can think of is to hide the fact that they have someone amongst us already.'

I was expecting her to laugh, but she didn't; she frowned. 'You're serious, aren't you?'

'Someone at the top.'

'Have you told Bret this theory?'

'Dicky thinks we should keep it to ourselves.'

'So Dicky's in on it.'

'Whatever's wrong with Dicky, no one could believe he might be a double agent. The Russians would never employ a twit like him. So I've agreed to keep everything on Trent confidential.'

'Everything?'

'Everything relevant.'

She moved her head as if trying to see me in a new light. 'You're hiding material from Bret? Why, that means you're hiding it, in effect, from the D-G and the committee.'

'In effect, yes.'

'You've gone crazy, darling. They have a name for what you're doing. They call it treason.'

'It's Dicky's idea.'

'Oh, that's different,' she said with heavy irony. 'If it's Dicky's idea, that's all you need say.'

'You think it's that crazy?'

She shook her head as if lost for words. 'I can't believe all this is happening. I can't believe I'm standing here and listening to you spout this absolute and ridiculous nonsense.'

'Let's go and see our son win the Olympics,' I said. She said, 'Poor little Billy, he's convinced he's going to win.'

'But you're not,' I said.

'He's a sweet child,' said Fiona, 'but I'm sure he'll finish last.'

'You don't have a drinks cabinet on this level, do you?'

'No alcohol in the yellow submarine, by order of the D-G,' said Fiona.

'For my next birthday,' I said, 'a hip flask.'

Fiona pretended she hadn't heard.

We got to Billy's school at 7.45 so I went inside without that drink I'd promised myself. It was a typical state school, designed in the sixties by the sort of architect who worked with the radio going. It was a giant shoebox that would have been totally featureless but for the cracks in the hardboard and the rust dribbles down the walls.

This evening of sporting events took place in a huge glass-fronted building adjoining the exercise yard. About three dozen dutiful parents, having purchased programmes, were perched on metal folding chairs at the chilliest end of the gymnasium. The young bearded headmaster, wearing the colourful and voluminous scarf of some provincial university, told us to hurry because we were late and reminded us that it was forbidden to walk on the wooden floor without gym shoes. Since I had neglected to equip myself with the right shoes, I walked round the gym while the senior boys performed knee bends to the sound of Pink Floyd on a tape recorder that hissed.

There was no room for us with the other parents, so I helped Fiona onto a vaulting horse and got up there alongside her. The headmaster gave me a disapproving look, as if he had decided I was the sort of man who might walk back across his polished floor.