In the middle of the night, the doorbell rings.

It’s about 1.30am, and I’m checking my email before turning in. My lights are on and I’ve not bothered to close my curtains. I had left the house during the day, returning very late and a little drunk. So as I’m emailing away at my desk by the curtainless window, I can probably be seen from the darkened street outside. Or watched.

The moment the doorbell sounds, my somewhat feeble reaction – after the surprise – is to turn off my lights and pretend I’m asleep, or that I am not in. I am, after all, a creature of timidity and detachment, and have only two modes: anxious and really, really anxious. A tightened stomach is my usual reaction to anything unexpected. And to much that is entirely expected, too.

‘Not me,’ I think as I hit the light switch. ‘Let it not toll for me. Or if it’s for anyone who can help, let it be one of the other tenants who answer. Not me. Please.’

Again the bell goes, breaking the night like a siren. This time, I faintly hear the other bells being tried. But no one else is shifting from their flats. I muse that it could well be a fellow resident who’s forgotten their front key.

So I go downstairs. And I open the door.

It’s a man I don’t know. He’s drenched in the rain with no umbrella, hat or hood. He bears a passing resemblance to the Cockney actor Phil Davis: 40-ish, a thin, long and boney face, light sandy hair. He’s wearing one of those fluorescent yellow jackets favoured by outdoor workers of all kinds, from civil engineers and architects to stewards at rock festivals. And he is also wearing an expression of anguished apology.

‘I’m really sorry to disturb you so late,’ he begins. And then he stops. I attempt a kindly smirk.

‘Well, go on, then.’

And he tells me that he lives around the corner. That his car broke down in Lewisham. That he doesn’t have quite enough money to pay the tow truck driver. That he badly needs his car in order to collect his wife in the morning. So could I possibly – and he’s SO sorry about this – could I possibly lend him the £18 he needs to pay the driver? Well, he says, call it £20. If I want, he’ll leave me his mobile phone by way of security. I tell him not to bother.

‘Where do you live, exactly?’ I ask. And he hesitates.

‘Southwood.’

‘Southwood what?’ There’s a few streets in the area which share this prefix. Southwood Lane. Southwood Avenue.

‘Southwood Lawn. 40 Southwood Lawn.’

There IS a Southwood Lawn Road around the corner, and though I’ve never heard anyone abbreviate it like this before, I suppose it’s possible he lives there. To my wary Londoner shame, I don’t know who lives opposite, let alone around the corner.

Something about his jacket, his manner and the time of night convince me. I find myself digging out a £20 note and handing it over. Part of me is doing so just to get rid of him, and in the hope he won’t bother anyone else. I add that I’m currently jobless and so can’t really afford it, but that I’m obliging him because he is a fellow human being in need. What I don’t add is that I’ve been reading about the Quakers, who see the good in everyone, and the God in everyone. And that I’m a little drunk.

He thanks me profusely, promises to repay me in the morning via an envelope through the letter box, then returns to the rainy darkness that spawned him. His expression of mortified apology remains in place throughout, even after I give him what he wants. I feel sorry for him. Which is the whole idea.

It’s now two days later, and there’s no sign of any envelope. So I wonder if I’ve been the victim of what’s called a damsel-in-distress scam. If so, I have to admire the man’s rain-soaked resolve, his Oscar-winning performance, and his sheer nerve. To ring a stranger’s doorbell in the middle of the night and simply ask for money: that takes a talent of a kind. I wonder if he had been watching me from the street earlier, my open curtains advertising that I was awake, alone and had a face that suggested I’d be kind enough to help someone in need. Or gullible enough to believe his story.

If he was indeed a crook, I’m grateful that he took off with only £20 in cash, nothing more, and left me entirely unstabbed. And I’ll be more on my guard next time. ‘Tuition fee’ says my father at any mistake that costs money.

And I will advise my London friends to look out for a man in a yellow fluorescent jacket asking for financial aid, who vaguely resembles Phil Davis. You know, I will say to them, that Cockney actor who’s in lots of things. Vera Drake. White Teeth. Notes On A Scandal – he’s the other teacher who fancies Cate Blanchett. That’s him. Well, not really him, obviously. I realise actors in the British film industry aren’t exactly rolling in it, but when it comes to finding an income between jobs, even they must draw the line at doorstepping strangers in the middle of the night.