Only a couple of days ago I discovered a few hardened pellets in the corner of a bedroom. Beautifully and regularly round, had they been heavier they would have made good marbles. I threw them away. I should've kept them. I can see why Chris Ofili gets excited about dung. This is what happened... Dear old, bloody old London. From the window of my little room at the back of a tallish, redbrick late-Victorian house in Highbury (close to Green Lanes, the longest road in London, which itself borders on the wildness of Hackney) the scene is quiet and lush in an inner-city, back-gardenish sort of way. Boxy red-brick public housing is off to the left, while squat Victorian villas, privately-owned, slope off to the right. This is an inner-city scenario, with the generally less well off, in their low-density housing 'solutions', having to put up with the better off in their yellowish 'London stock' brick cubes. Both communities do their best to ignore each other, the poor, quite rightly, angry with the rich for being rich, the rich resenting the poor for holding back local property prices, while all around is a pleasant profusion of chestnut trees and plane trees and little gardens with hedges and lawns, a rockpool here, rare plants there, weeds elsewhere. Earlier this year, somewhere in these back gardens, there was a brutal killing.

Or at least I have strong reason to believe there was. My daughter Rose had a pet rabbit called Floppy. Long-eared, of a breed which I think is called a Lop, Floppy lived with us for around eight months until the beginning of summer this year, and we had the pleasure of watching him grow into a fat, toilet-trained, sexually-aggressive but otherwise affectionate ball of fur, who, until his expensive castration, would attempt to have his way with human legs, cushions and any of the many cats in the neighbourhood. My wife noticed what she described as his 'sexuality', and I think he eyed her up more than once. I wasn't jealous. I did nothing to discourage it.

Never very good at home improvements, I did my best with bricks, chicken wire, staves and odd bits of wood to secure the garden and provide Floppy with limited freedom. It worked for a while, but he soon extended his range beyond my control.

Towler, a major cat-lover a couple of doors away, insisted. She said he'd be much quieter, settled and compliant afterwards. I didn't doubt it, but I was nevertheless very sorry to see the back of Floppy's balls. What an endowment. A pinkish corkscrew pizzle of a penis poked out when aroused, which was often, but much more truly impressive was the fine pair of testicles, which lolloped in his hind quarters like a pair of cylinders in a double-barrelled scrotum of smooth puce skin. It put me in mind of the sure fact that somewhere in the distant past we had shared a common ancestor.

Pre-op he had the run of three gardens on a regular basis, with occasional forays into another four, where he was known and from which he was affectionately returned. Post-op, frankly, he was never quite the same rabbit. At least, not for me.

My wife was the first to see the fox at close quarters, months before, back in the early days when we kept Floppy outside in a hutch. Floppy banged his back legs hysterically against the sides of his dwelling and Old Foxy just stared at him. This was the incident that caused us to bring him in and begin his apprenticeship in the liberal, free-ranging house-trained ways that eventually led to his downfall.

I maintain, because I still feel guilty about it, that the brevity of Floppy's life was more than made up for by its quality. He got around. He explored. He chased cats for sex until he fell over with fatigue and contentment. He moulted. He cleaned himself and kept in good shape. He had his favourite sleeping places.

I thought we'd cracked it and he was in the clear. But one night Floppy went out and met Old Foxy.

Rose put lost rabbit notices on the trees in our road. No evidence was found, but somehow I just knew. Old Foxy had been out there, all the time, playing the long game.

A couple of weeks later, while driving north not a hundred yards from here in the mid summer's evening gloom, I saw the unmistakeable outlines of a fox cross the road with a small animal hanging from its mouth. It wasn't Floppy. He'd been long gone by then. But I was sure I'd seen the perpetrator.

Looked like a goddamn werewolf to me.