I was sitting waiting for Silas to return from upstairs. The narrow stone-framed windows let in only a thin slice of grey afternoon light. The log fire burning brightly in the big stone hearth filled the air with a smoky perfume and provided the light by which to see the drawing room with its battered old sofa and uncomfortable chairs, their shapes only vaguely apparent under the baggy chintz covers. In front of the fire there was a tray with the remains of our tea: silver teapot, the last couple of Mrs Porter's freshly made scones and a pot of jam with a handwritten label saying 'Whitelands – strawberry'. It might have been a hundred years ago but for the big hi-fi speakers that stood in the far corners of the room. This was where Silas spent his evenings listening to his opera records and drinking his way through his remarkable cellar.

'Sorry about these interruptions,' he said as he fiddled to close the ancient brass door latch. He clapped his hands and then went to warm them at the fire. 'Fresh tea?'

'I've had enough tea,' I said.

'And it's too early for a drink,' said Silas.

I didn't reply.

'You tell me a lot of things,' he said, pouring the last tepid remains of the tea into his cup. 'And you want me to make them fit together nicely, like pieces of a jigsaw.' He sipped the cold tea but pulled a face and abandoned it. 'But I don't see any causal connection.' Sniff. 'Either it's much colder today or I'm getting flu… or maybe both. So this accountant fellow, Prettyman, was killed in Washington by some hooligan, and now his wife has been promoted? Well, jolly good, I say. Why shouldn't the poor woman be promoted? I've always thought we should look after our own people to the best of our ability.'

There was a long silent rumination until I helped him remember the rest of it. 'And then there was Bret Rensselaer,' I said.

'Yes, poor Bret. An awfully good chap, Bret; injured on duty. An episode in the very best traditions of the service, if I may say so. Yet, you seem indignant that he survived.'

'I was surprised to see him arise from the dead.'

'I can't see what you're getting at,' said Uncle Silas. 'Aren't you pleased by that either?' he scratched his crotch unselfconsciously. He was a strange old devil; fat and dishevelled, with a coarse humour and biting wit that was not funny to those who found it directed at them.

'There are too many things happening… funny things.'

'I really don't follow your reasoning Bernard.' He shook his head. 'I really don't.' Uncle Silas had always been able to twist the facts to suit his hypothesis. 'It's not a bit of good, you sitting there glaring at me, dear boy.' He paused to take out a big red cotton handkerchief and blow his nose violently. 'I'm trying to prevent you making a bloody fool of yourself.'

'By doing what?'

'By bursting in on poor old Dodo and giving him the third degree.' Old Silas must have been the last living person still using expressions like third degree.

'Did you know him well?'

'Yes, I remember him well,' said Silas, sitting back in his armchair and staring into the fire. 'His real name was Theodor – Theodor Kiss – so he preferred to be Dodo. A keen worker: bright as a button. A good science degree at Vienna University and a good administrative knack. Lots of languages and dialects too. Dodo could effortlessly pass himself off as a German. Or as an Austrian. Effortlessly!'

'Amazing,' I said.

'Oh, I know you can do the same thing, Bernard. But it's quite an unusual feat. Not many Germans can do it, as I know to my cost. Yes, Dodo was a remarkable linguist.'

'He worked for Gehlen,' I said, to remind Silas that this paragon was an ex-Nazi.

'Most of the best ones had worked for him. They were the only experienced people available for hire. Of course, I never used any of them,' said Silas, perhaps wanting to deflect my wrath. 'Not directly. I stayed clear of Gehlen's ex-employees. Lange Koby took him away with the rest of his gang… What did he call them…?'

'Prussians,' I supplied.

'Yes, "Koby's Prussians", that's right. How could I forget that? My memory is going wonky these days.'

I said nothing.

'Your father too. He wouldn't go near any of them. He was upset when you worked for Lange Koby.'

'I teamed up with Max,' I said. 'Koby came as part of the deal.'

Silas sniffed. 'You should have stayed with your father, Bernard.'

'I know,' I said. He'd touched a nerve.

We sat silent for a few minutes. 'Your Dodo is all right,' said Silas, as if he'd been thinking deeply about it. 'Perhaps a bit too keen to demonstrate his valour, but so were all the ones who'd changed sides. But Dodo, when he settled down he became a loyal, sensible agent; the sort of fellow I would have expected you to be specially sympathetic towards. A man like that must be excused an indiscretion now and again. What?' He got out his handkerchief and wiped his nose.

'Indiscretion?'

'I'd say the same for you, Bernard,' he added before my indignation boiled over. 'Have said it, in fact,' he persisted, to make sure I knew I was indebted to him.

He stopped, perhaps waiting for some gesture of appreciation or agreement. I nodded without putting too much into it. Ever since arriving here I had been considering ways to ask him about the mad allegations about my father. Silas had known my father as well as anyone still alive. They'd served together in Berlin, and in London too. Silas Gaunt could solve just about any mystery that arose out of my father's service if he wanted to. If he wanted to; there's the rub. Silas Gaunt was not a man much given to revealing secrets, even to those entitled to know. And this wasn't the time to ask. That much was clear just from looking at the old man's face. He was not enjoying my visit, despite all the smiles and nods and pleasantries. Perhaps he was just worried about me. Or about Fiona or about my children. Or about Dodo. 'I know you have, Silas,' I said. 'I appreciate it.'

'I want you to promise not to go in there ranting and raving,' said Silas. 'I want you to promise to go along there and talk to him in a conciliatory manner that will make him see your point of view.'

'I'll try,' I said.

'We all have a lot of old comrades in common: the Gebhart twins, "Baron" Busch who took you to Leipzig, Oscar Rhine who said he could swim across Lubeck Bay but couldn't… ' Silas had tried to make light of his list of departed colleagues but couldn't maintain the levity. He wiped his nose and tried again. 'We all grieve for the same old friends, Bernard: you, me, Dodo…No sense in quarrelling amongst ourselves.'

'No,' I said.

'He's been in the business even longer than you have,' said Silas, 'so don't start talking down to him.' This was Silas at his avuncular worst. Sometimes I wondered if he ever spoke to the D-G like this, for I knew that Silas regarded all of us as children attempting a man's job at which he'd excelled.

'No, Silas,' I said, and I must have allowed some trace of my scepticism to show, for there was a twitch of the face that I'd learned to recognize as a sign of anger to come.

But the anger didn't come, or at least it didn't show. 'Tell me again about Bret Rensselaer; is he coming back to work?'

'No chance,' I said. 'He's too sick and too old.'

'They say he wanted Berlin,' said Silas.

'Yes,' I said. 'At the time the rumours said Frank would get his K and retire, and Bret would get Berlin.'

'And then Bret would get his K and retire,' said Silas, completing the scenario that everyone had said was inevitable up to the time that things went wrong and Bret got shot. 'So what was the long-term plan for Berlin?'

I looked at him and wondered what everyone in the Department must have wondered at some time or other: why Silas Gaunt had never got the knighthood that usually came with such retirements. 'Come along, Silas,' I said. 'You know more about what goes on in the minds of the men on the top floor than I will ever find out. You tell me.'