‘Hydro-den-whatery?’

‘Hydro-dendrology. It is the science of growing trees in water.’

I too gave my groin a thoughtful but much needed scratch.

‘This is his house,’ said the boy. And I looked up to see it.

The houses of the Butts Estate were of the Georgian ilk. Mellow pinky-bricked and proud-proportioned. The gardens were well tended and the folk who lived here were grand. A professor on the corner there and, deep amongst the trees, the Seamen’s Mission. An old sea captain kept the place, but none of us had seen him. There was peace and quiet here and there was history.

We never got much in the way of local history at school. But we knew all the major stuff anyway. It had been passed down to us by our parents. ‘That’s where Julius Caesar crossed the Thames.’ ‘That’s where King Balm fell during the famous Battle of Brentford.’ ‘That is the site of the coaching inn where Pocahontas stayed.’ And, most interestingly of all, ‘That is the house where P. P. Penrose was born.’ Prior to Mr Doveston, P. P. Penrose was undoubtedly Brentford’s most famous son: author of the best-selling books of the twentieth century, the now legendary Lazlo Woodbine novels.

Throughout his life it was popularly believed that he had been born on the Lower East Side of New York. He affected a Brooklyn accent and always wore a fedora and trench coat. It was only after his tragic early death (in a freak accident involving handcuffs and a vacuum cleaner hose) that the truth finally came out (along with much of his lower bowel) — he had been born plain Peter Penrose in a house on Brentford’s Butts Estate. He had never been to New York in his life.

They never put a blue plaque up, but we all knew which house it was. The one with the blinds always drawn. In the summer, coachloads of American tourists would arrive to peer at those blinds. And our friend Billy, who knew more than was healthy for one of his age, would take his mum s vacuum cleaner along. The Americans would pay Billy to let them pose with it.

But I have nothing new to add on the subject of Penrose. And can do no more than recommend to the reader who wishes to delve further into the man, his work and his domestic habits, that they sample Sir John Rimmer’s excellent biography: Some Called Him Laz: The man who was Woodbine.

Or the article on auto-erotic asphyxiation that was published in the last-ever issue of Gagging for It! magazine, December 1999.

‘I’m gagging for a drink,’ I said. ‘Do you think that Uncle Jon Peru has lemonade?’

‘He only drinks filtered water.’ The boy Doveston reached out for the big brass knocker. ‘Now remember what I told you to say,’ he said in a serious voice.

‘What was it you told me to say?’ I asked, as I hadn’t been listening at the time.

‘That you are my brother Edwin and you share my interest in plants.’

‘But you don’t have a brother Edwin.’

The Doveston shook his scrofulous head. ‘Do you want to see the monsters or not?’

‘I do,’ I said. And I did.

Normally, on a warm summer’s evening like this, I would have been down at the canal, fishing for mud sharks. But the Doveston had promised me that if I gave him a shilling, he would take me to meet a man who had monsters in his greenhouse and might even let me feed them, if I asked him nicely.

It was not the kind of offer a nine-year-old boy could refuse.

The Doveston tugged upon the big brass knocker. ‘We’ll have to wait for a bit,’ he said. ‘He has to check out the street.’

I made the face of puzzlement.

‘Just wait,’ said the boy. So we did.

After what seemed a considerable wait, during which thoughts began to enter my head that perhaps I didn’t really want to see monsters at all and would rather have my shilling back, we heard the sounds of bolts being drawn and the big front door eased open a crack.

‘Password,’ came a whispered voice.

‘Streptococcus,’ said the Doveston, naming the Gram-positive spherical bacterium responsible for the outbreak of scarlet fever which had all but wiped out class three in the winter before.

‘Enter, friend, and bring your brother.’

And so in we went.

When the front door closed it was rather dark and our host switched on the light. As I hadn’t been expecting anything in particular, I was not at all surprised by what I saw. The hall was high and wide and rather grand. A patterned rug upon a polished floor. A jardinière with peacock plumes. A glimpse or two of splendid rooms. A bamboo stand with hats and coats, but very little more.

The sight of our host however, did surprise me. With the Doveston’s talk of the Royal Engineers and the SAS, I had at least been expecting a man who looked like an ex-soldier. But Uncle Jon Peru Joans was small and weedy. His cheekbones stuck out like a cyclist’s elbows and his chin was that of Mr Punch. His baldy head was narrow and high and mottled as a pigeon’s egg. His nose was slim as a paper dart, but his eyes were the very most worrying part.

Some months before I had sneaked in through the back door of the Odeon cinema in Northfields to see an X-certificate film called Mondo Cane. It was a documentary about curious customs around the world and included a lot of footage of bare-breasted native women jumping up and down. But the sequence that really stuck in my mind was the bit about a restaurant in China where they served monkeys’ brains. Monkeys’ brains from live monkeys. They had these special tables with little holes in the middle and the monkeys' heads were stuck up through these and held in place. And then, as coolly as you might peel an orange, the waiters would peel off the top of the monkeys’ heads and the patrons would fish out the brains with little spoons and eat them.

It was the look in the eyes of those monkeys that I will never forget. The terror and the pain.

And Uncle Jon Peru Joans had eyes like that. They looked everywhere and nowhere and they put the wind up me.

‘So this is your brother Edwin,’ he said, his gaze darting over my head. ‘Come to see my beautiful boys.’

I wished him a good evening and called him sir, because adults always respond to politeness. He reached forward to pat my head, but he must have noticed me ffinching and so instead he just said, ‘Can he keep our secret?’

‘Oh yes, Uncle.’ The Doveston grinned. ‘He is my brother, after all.’

‘Then I shall trust him as I trust you.

The Doveston winked in my direction.

Uncle Jon Peru Joans led us down his hall. ‘It has been a trying day,’ he told us. ‘The secret police have stepped up their campaign of harassment.

‘The secret police?’ I asked.

‘Oh yes,’ said the weedy man. ‘I am followed everywhere. They pose as passers-by, as window-cleaners and postmen, shopkeepers and mothers pushing prams. They know that I’m on to them and this makes them worse. Only this morning, when I went out to buy a packet of cigarettes—’

‘Snowdon,’ said the Doveston.

The uncle turned upon him, the wild eyes wilder yet.

‘I can smell the smoke,’ the boy explained. ‘You’ve only just put one out. Snowdon is a menthol cigarette. It has a most distinctive smell.’

‘Good boy,’ said the uncle, patting the Doveston’s shoulder. ‘I change my brand every day to keep them guessing.’

‘The secret policemen?’ I asked.

‘Exactly. And when I went into the shop there were two of them in there. Dressed up to look like old women with shopping bags. They were watching to see what I’d buy. They keep a record of everything I do. It all goes on file in the secret headquarters at Mornington Crescent.’

‘Why do they do this?’ I asked.

‘Because of my work. Hasn’t Charlie told you?’

‘Charlie?’

‘I thought it would be better coming from you,’ said the Doveston.

‘Good boy once more.’ The weedy man led us into his kitchen, which smelled as bad as it looked. There were bags of rubbish piled up the walls and boxes and boxes of paper.