Hud had a damp cold handclasp that I supposed he couldn't help, and if he had lately had an oiled black pony-tail and a black moustache-beard mouth-circling combination, they had very likely been dyed. His present hair colour was the dark-lightly-flecked-with-grey that a passing girl-friend had told me couldn't be faked, and he'd had a cut in a swept-back and duck-tailed style straight from the films of James Bond. Distinguished. Impressive, one had to admit. It inspired trust.

My father's own mat of natural dark close curls was cut to display to advantage the handsome outline of his skull. Expert stuff. Ah, well.

Hudson Hurst was overpoweringly pleasant to Polly. Smile and smile, I thought, remembering Hoopwestern: smile and smile and shake the hands and win the votes. He flicked me a glance, but I wasn't important.

Sweet Mrs Prime Minister appeared at my elbow and asked if I was having a good time.

'Oh, yes. Splendid, thank you.'

'You look a bit lost. Come with me.' She led me across to the far side of the big room and stopped beside a sharply dressed woman who reminded me strongly of Orinda. 'Jill, dear, this is George Juliard's son. Do look after him.'

Jill gave me a comprehensive head-to-toe and stared at Mrs Prime Minister's retreating back without enthusiasm.

'I'm really sorry,' I said, 'I don't know your name.'

'Vinicheck. Education.'

'Minister of?'

Her grim lips twitched. 'Certainly.'

She was joined by another woman in the simplest and best of current fashion: another Orinda-clone. Secretary of State for Social Security.

She said bluntly, 'Where does your mother get her clothes?'

I followed her gaze across the room and saw Polly talking unselfconsciously to the man with flat white hair and circular eyes: the Home Secretary. Polly's clothes, as always, had nothing to do with popular opinion but very clearly revealed her individual character.

Jill Vinicheck (Education) kindly said, 'Your father may have a bright career in front of him, but your mother will have to change the way she dresses or she'll be clawed to bits by those bitches who write about fashion in the newspapers.'

The Secretary of State for Social Security agreed. 'Every woman in politics gets the hate treatment. Haven't you noticed?'

'Oh, not really, no.'

'Your mother's skirt is the wrong length. You don't mind me telling you? I'm only being helpful. Frankly, it would be the wrong length whatever length it was, according to the fashion bitches. But you can pass on some tips to her from us, if you like.'

'Er...'

'Tell her,' Jill Vinicheck said, enjoying herself, 'never to buy clothes in shops.'

Social Security nodded. 'She must have them made.'

Jill Vinicheck: 'Always wool or silk or cotton. Never polyester, or tight.'

'There's a marvellous man who could make your mother really elegant, with her long thin figure. He totally changed the way the papers write about us now. They discuss our policies, not our clothes. And he doesn't do it only for women. Look at the change in Hudson Hurst! Hud frankly looked a bit of a gangster, but now he's a statesman.'

'No time like the present,' Jill Vinicheck said with the briskness that had no doubt propelled her up the ladder. 'Our wand-waving friend is here somewhere. Why don't we introduce him to your mother straight away?'

'Er...' I said. 'I don't think she '

'Oh, there there he is,' said Social Security, stepping sideways and pouncing. 'Let me introduce you...' he is,' said Social Security, stepping sideways and pouncing. 'Let me introduce you...'

She had her hand on his arm and he turned towards her, and I came face to face with A. L. Wyvern.

Alderney Anonymous Lover Wyvern.

No wonder Education and Social Security had reminded me of Orinda. All those years ago his ideas had dressed her, too.

I knew him instantly, but it took him several seconds to add four years to my earlier appearance. Then his face hardened to ill-will and he looked disconcerted, even though with my father in the Cabinet he might have considered that he and I might both be asked to the families' Christmas reception. Maybe he hadn't given it a thought. In any case, my presence there was to him an unwelcome surprise.

So was his to me.

Education and Social Security were looking puzzled.

'Do you two know each other?' one of them asked.

'We've met,' Wyvern said shortly.

His own appearance, too, had changed. At Hoopwestern he had made a point of looking inconspicuous, of being easily forgettable. Four years later he wasn't finding it so simple to fade into the wallpaper.

I had thought him then to be less than forty, but I now saw that to have been probably an underestimate. His skin had begun to show a few wrinkles and his hair to recede, and he was now wearing glasses with narrow dark frames. There was still about him, though, the strong secretive aura of introverted clout.

At the Downing Street Christmas party there was no overt sign of the sleeping anger that had blazed across Orinda's face and nearly killed her. He was not this time saying to me aloud in fury, 'One day I'll get you,' but I could see the intent rise again in his narrowed eyes as if no interval for second thoughts had existed.

The extraordinary response I felt was not fear but excitement. The adrenalin rush in my blood was for fight, not flight. And whether or not he saw my reaction to him as vividly as I felt it, he pulled down the shutters on the malice visible behind the dark-framed lenses and excused himself with the briefest of courtesies to Education and Social Security: when he moved slowly away it was as if every step were consciously controlled.

'Well!' exclaimed Jill Vinicheck. 'I know he's never talkative, but I'm afraid he was... impolite.'

Not impolite, I thought.

Murderous.

After the reception Polly, my father and I all ate in one of the few good restaurants in London that had taken the din out of dinner. One could mostly hear oneself speak.

My father had enjoyed a buddy-buddy session with the Prime Minister and Polly said she thought the circular eyes of the Home Secretary were not after all an indication of mania.

Didn't the Home Secretary, I asked, keep prisoners in in and chuck illegal immigrants and chuck illegal immigrants out out?

More or less, my father agreed.

I said, 'Did you know there was a list on a sort of easel there detailing all the jobs in government?'

My father, ministerially busy with broccoli that he didn't actually like, nodded, but Polly said she hadn't seen it.

'There are weird jobs,' I said, 'like Minister for Former Countries and Under Secretary for Buses.' Polly looked mystified but my father nodded. 'Every Prime Minister invents titles to describe what he wants done.'

'So,' I said, 'theoretically you could have a minister in charge of banning yellow plastic ducks.'

'You do talk nonsense, Benedict dear,' Polly said.

'What he means,' my father said, 'is that the quickest way to make people want something is to ban it. People always fight to get what they are told they cannot have.'

'All the same,' I said mildly, 'I think the Prime Minister should introduce a law banning Alderney Wyvern from drinking champagne at No. 10 Downing Street.'

Polly and my father sat with their mouths open.

'He was there,' I said. 'Didn't you see him?'

They shook their heads.

'He kept over the far side of the room, out of your way. He looks a bit different. He's older, balder. He wears spectacles. But he is revered by the Minister of Education, the Secretary of State for Social Security and the Secretary of State for Defence, to name those I am sure of. Orinda and Dennis Nagle were kindergarten stuff. Alderney Wyvern now has his hands on levers he can pull to affect whole sections of the nation.'

'I don't believe it,' my father said.

'The dear ladies of Education and Social Security told me they had a friend who would do wonders for my... er, mother's wardrobe. He had already, they said, turned Hudson Hurst from a quasi mobster into a polished gent. What do you think they give Alderney in return?'

'No,' my father said. 'Not classified information. They couldn't!'

He was scandalised. I shook my head.

'What then?' Polly asked. 'What do they give him?'

'I'd guess,' I said, 'that they give him attention. I'd guess they listen to him and act on his advice. Orinda said years ago that he had a terrific understanding of what would happen in politics. He would predict things and tell Dennis Nagle what to do about them and Orinda said he was nearly always right. Dennis Nagle had his feet on the upward path, and if he hadn't died I'd think he'd be in the Cabinet by now with Wyvern at his shoulder.'

My father pushed his broccoli aside. A good thing his broccoli farmers weren't watching. They were agitating for a broccoli awareness week to make the British eat their greens. A law to ban excess broccoli would have had healthier results.

'If he's so clever,' Polly asked, 'why isn't he in the Cabinet himself?'

'Orinda told me the sort of power Alderney really wants is to be able to pull the levers behind the scenes. I thought it a crazy idea. I've grown up since then.'

'Power without responsibility,' my father murmured.

'Allied,' I said ruefully, 'to a frighteningly violent temper which explodes when he's crossed.'

My father hadn't actually seen Wyvern hit Orinda. He hadn't seen the speed and the force and the heartlessness; but he had seen the blood and tears and they alone had driven him to try to retaliate. Wyvern had wanted to damage my father's reputation by provoking my father to hit him. I dimly understood, but still hadn't properly worked it out, that attacking Wyvern would, in the end, destroy the attacker.

My boss Evan agreeing, I'd tied in the No. 10 Thursday evening reception with a Friday morning trip to meet a claims inspector to see if a haybarn had burned by accident or design (accident) and was due to stay again on Friday night in London with Polly and my father, before going to ride at Stratford-upon-Avon on Saturday, but en route I got a message to return to meet my father in Downing Street by two that Friday afternoon.

'I thought you might like to see more of the house,' he said cheerfully. 'You can't see a thing at those receptions.'

He had arranged for one of the household staff called a messenger to accompany us and show us round officially, so we went up the yellow staircase again, spending longer over the pictures, and wandered round the three large drawing-rooms leading off the ante-room at the top of the stairs: the white drawing-room, the green drawing-room and the pillared drawing-room where they'd held the reception.

The messenger was proud of the house which he said looked better and was better looked after than at any time in its rickety history. It had once been two houses back to back (rather like the burnt shops of Hoopwestern): the small Downing Street house facing one way, and a mansion to the rear of it facing the other. The interior layout over two and a half centuries had been constantly redesigned, and a modern refurbishment had bestowed overall an eighteenth-century ambience that hadn't been there before.

'The green drawing-room used to be the blue drawing-room,' the messenger said happily. 'All the beautiful plaster work on nearly all the ceilings is relatively new. So are the classical mantels over the doorways. It all looks now like it always should have done, and never did.'

We admired it all copiously, to his satisfaction.

'Through here,' he said, marching off into one corner of the pillared drawing-room, 'is the small dining-room.' (It seated twelve in comfort.) Beyond that is the State Dining-Room.' (Dark panelled walls, seats for twenty-four.) He told us about all the paintings in every room. I thought of all the past prime ministers for whom this graceful splendour had not existed, who had used this building as an office. It seemed a shame and a waste, somehow.

Back in the ante-room to the drawing-rooms our guide told us, pointing, 'Up those stairs is the Prime Minister's private apartment, and behind that locked door is his own personal room where no one goes unless he invites them. And downstairs...' he led the way expertly, via a lift to the ground floor '... along this passage, as of course you know well, sir, is the ante-room to the Cabinet Room itself, sir, and I'll leave you to show those yourself to your son, sir, and I'll see you again just on your way out.'

My father thanked him sincerely for his trouble, and I reflected, slightly overwhelmed, that I'd never before given much of a thought to the living legacy of history my father hoped to inhabit.

The ante-room was any ante-room: just a gathering place, but with brilliant red walls.

The Cabinet Room, at the rear of the old mansion section, was long, with tall windows down one side and across one end, facing out into a peaceful-looking walled garden.

Irish terrorists had lobbed a bomb into that garden while all the Cabinet ministers were in the building. The bomb had done little damage. The grass now looked undisturbed. Peace was relative. Guy Fawkes could rise again.

Extraordinarily, Sir Thomas Knyvet, the magistrate who arrested Guy Fawkes red-handed with his barrels of gunpowder, lived in a house on the exact spot where the developer George Downing later built No. 10.

'This is where I usually sit,' my father said, walking down the room and coming to rest behind one of the two dozen chairs. 'That chair with arms, halfway along the table, that is the Prime Minister's chair. It's the only one with arms.'

The long table down the centre of the room wasn't rectangular but a much elongated oval, in order, my father explained, for the Prime Minister to be able to see the various members more easily.

'Go on, then,' I teased him. 'Take the arms.'

He was half embarrassed, half shy, but he couldn't resist it. There was only his son to see. He crabbed sideways round the table and sat in the chair with arms; he nestled into it, resting his wrists, living the dream.

Above and behind him on the wall hung the only picture in that room, a portrait of Sir Robert Walpole, the first to be given the title Prime Minister.

'It all suits you,' I said.

He stood up self-consciously and said, as if to take the emotion out of the moment, 'The chair opposite the Prime Minister is normally where the Chancellor of the Exchequer sits.'

'And how many of you put your feet up on the table?'

He gave me a disgusted look. 'You're not fit to be taken anywhere.'

We returned to the front hall, my father looking at his watch. The messenger appeared as if on cue to see us off the premises, and I wondered vaguely if there were interior monitoring video cameras which would be merely normally prudent to trace the comings and goings of visitors.

While we said lengthy farewells the front door opened and in walked the Prime Minister, followed by two alert young men: bodyguards.

The Prime Minister said, 'Hello, George,' without surprise and glanced at his own watch revealingly. 'Come this way. And you... er...'

My father said, 'Ben.'

'Ben, yes. The racerider. You come too.'

He led the way through the front hall and past the staircase into a crowded and busy office crammed with desks, office paraphernalia and people, who all stood up at his approach.

'Now, Ben, you stay here with these good people while I talk to your father.'

He went through the office, opened a door and gestured to my father to follow. The office staff gave me a chair and a friendly welcome and told me that I was in the room where all the real work got done; the running of the Prime Minister's life as opposed to his politics.

They told me that quiet though the house might seem on a Friday afternoon, almost two hundred people worked there in the buildings in connected offices and that someone had once counted how many times the front door of No. 10 had been opened and closed in twenty-four hours, and it was more than nine hundred.

At length, in response to one of the constant telephone calls, I was invited through the office and into the next room in the wake of my father, and found myself in a large quiet tidy place that was part office, part sitting-room.