It was a spur of the moment, late night thing. Tired, behind the wheel, and heading east on the Euston Road, I turned left just beside St Pancras, very suddenly and right across the bows of a cab. This on the eve of the ninth anniversary of the last time I deliberately drank alcohol, and with a police car right behind.

The young policeman asked me to breathe onto the palm of his hand. Interesting, I thought. Do alcohol molecules particularly adhere to the palms of hands, or did he not want to risk colds or worse (TB is prevalent in the area) or would he ask me to go further and suck his fingers? On the seat was a briefcase with a thousand in cash inside, and a bit earlier, in a supermarket bag on the floor, I'd had a long barreled Smith and Wesson .38 revolver, a gleaming stainless steel piece of Springfield, Mass. engineering, which I imagine, had circumstances stacked up slightly differently that night, might have required, at the very least, some further explanation, if not specialist legal advice.

And it would all have been Virginia's fault. She got a last minute call to go to Prague to produce something much more important (and, critically, at much higher rates of pay) leaving the director, Mike, and me to run round all over town collecting the props for our seat of the pants production. An exhausting few days in pursuit of the usual stuff - brassieres, high heels, bust display units, dead tropical fish, fake blood.

When I signed the release form behind the locked steel door at the armourers, the man told me to watch out. Of the thirty two emergency call-outs of the Metropolitan Police's rapid response sharpshooter unit in the capital last year, something like twenty eight involved 'irresponsible' use of firearms by directors and producers on location. Waving them about in the street. Threatening actors. Leaving them casually on car seats. And then the police have the temerity to send you the bill. No, it may not turn a hair in Arizona or Utah, but you just can't behave like that over here because, as we all know, this is a sensible country, full of sensible people. Eminently sensible people.

And I'm one of them. I'd left the revolver back in the studio, and I hadn't had a drink, and the cop wished me a safe journey home. The shoot went beautifully all week but as soon as we wrapped the weather changed and since then it's been big winds and big rain. Tornadoes of sodden rubbish funnel their way down the street. Forget the Union Jack. As if to welcome spring, the trees of London are fluttering with a different sort of bunting - torn plastic supermarket bags.

I really like them.