This article originally appeared in Standpoint magazine (October 2013 edition)

He was pushing her around. Right in front of me. There on the pavement. At rush-hour. In broad daylight. He — stocky, crew cut — was shoving her forward violently, then yanking her back, in a series of frenetic, push-pull movements. She was shrieking, he shouting in a language I couldn’t identify (which hardly narrows it down).

I was hurrying home from Shepherd’s Bush station, across one side of the triangle which is the Green, already late for supper (when we’re hosting, my wife gets strangely cross if I arrive after our guests).

But here was this.

The man’s aggression escalating, I decided there was nothing for it. I tried to squeeze in between them to separate the pair, to prize them apart. And it worked: immediately his fury was transferred on to me. With one hand he grabbed my collar, while the other he seemed to be winding up for a punch. We locked eyes: I could see they were silky but wild too, under the influence.

I tried to keep my body and head low, tucked in tight, to protect against blows.

He wheeled me round in a kind of mad balletic dance. I glanced round desperately for help. The crowd stepped aside to avoid us, like excrement smeared on the concrete, passers-by rather than onlookers —until one young black man stopped, took his headphones out of his ears, and promptly pulled me away from the clutches of my opponent.

But this was not the eventuality I had intended. Because rather than running for cover, the woman had stood frozen to the spot, looking on, as Gertrude says of Ophelia, “as one incapable of her own distress, like a creature native and indued unto that element”.

And then an older woman bounded up to me: “I saw everything! There are police! Just up ahead!”

So I stepped into the street and sprinted, along the kerb and against the traffic, knocking a beer out of someone’s hand as I ran, sending it to the ground fizzing and frothing. I finally found the pair of policemen.

“There’s a man!” — breathless — “a man assaulting a woman!”

The three of us ran back in the direction I had come from.

First we found the woman. Except that now she was alone. “That’s her!” I cried. Instantly shedding a third of our infantry, two of us continued on, myself and the rotund, mid-fifties silver fox I’ll call PC Lightning Strike.

We quickly arrived at a key juncture. Up ahead, the crowd streaming towards us away from the station; to my right, Shepherd’s Bush Green and various people retreating from us; to my left, a side-street, Caxton Road.

PC Lightning Strike waited on my lead. I tried to focus, to think, to recall some deeply submerged Jason Bourne-type muscle-memory. Which way would I go? I’d get off the main road, surely. But across the Green I couldn’t make out anyone who looked like the man. So instead I spun round and squinted down Caxton Road. Where I saw two men walking away with their backs to us. And one wore a bomber jacket I vaguely recognised. It was enough to go on.

As we headed down the side-street, the first man peeled off left into a pink housing block before the second man swivelled round and, catching sight of my fluorescent friend, suddenly made a run for it.

Now we’re both in pursuit. But PC Lightning Strike is not the competitor he once was, so I soon led the pack.

By now our man has turned into another street and exited frame. Arriving there well ahead of my now-struggling colleague, I decide to follow him.

Rounding the corner brings into view the surprising sight of the fugitive not speeding away but rather sprawled out on the kerb, having tripped himself up.

Resisting the urge to rush into round two, this time I keep my distance, waiting around as in some Road Runner cartoon, holding out for back-up. Who eventually arrives, panting heavily between pronouncements, and proceeds to read our man his rights.

It is now that our culprit decides to take his assault-tally to three. He lashes out, throwing a punch at PC Lightning Strike.

I watch as the two heavies struggle in what seems like slow-motion.

“Take your hand away from your pocket!” was, I felt, my cue to re-enter the fray. Sharing my colleague’s fear of a knife, I grab the man’s jacket and try to pull it off as PC Lightning Strike holds down his “base”, and our foe contorts his body like a toddler in a tantrum.

We manage to strip him of his jacket but our success only spurs him on. Somehow, he slips free of the officer’s grasp and is almost up and away. I can’t bear it: I jump on his back and tackle him to the ground, managing, as he falls, to catch my hand between his body and the pavement.

As I hold him to the floor, my fellow-musketeer finally manages to manacle the man. And then, at last: sirens, van, more policemen.

As I hang around in the light rain to give my contact details-I am now unforgivably late for supper-my abiding thoughts are ones of self-doubt. As the prisoner sits cross-legged drunkenly wailing, and cursing me in particular, I wonder whether maybe I had escalated the situation. Maybe I had simply misinterpreted how people from beyond the Adriatic choose to express affection? Maybe I was butting my nose into other people’s business?

When I get home — white, shaking — I plunge into the extremely good excuse that my wife thinks is bull. But when my guests suggest that perhaps the reason the woman didn’t flee was because I had disrupted a prostitute and her pimp merely haggling over tips or, worse, stumbled across a West London human-trafficking ring, I pour myself another whisky. My only consolation: at least the baddie’s behind bars. Or at least that’s what I thought.

A week later PC Lightning Strike came to my office to take a statement.

“Well, sir, first let me say, this is hugely embarrassing.”

“How’s that?”

“It really is, very unfortunate.”

“What is?”

“Well, Wandsworth’s pace clock-”

“Huh?”

“Well, see, sir, it ran out.”

“What’s a pace clock?”

“When you’re arrested, right, you have to be charged within 24 hours. But that night, the only jail space was in Wandsworth. And he was so drunk they couldn’t speak to him straight away. Thing is, they didn’t tell us when they started his clock.”

“So?”

“It didn’t leave us enough time.”

OMG. They’ve released him into the wild.

While I’m imagining the man and his posse marauding the streets of West London in search of me, PC Lightning Strike pulls out a tatty questionnaire.

“What immediately strikes you about this, sir?’

All the text was in black and white apart from two little words in red: “ADDRESS: UNKNOWN.”

“And you let him go?”

“Don’t you worry yourself, sir. I promise you,” PC Lightning Strike reassures me, “when he turns up we’ll be ready.”