I witnessed two such site-specific arts events last week, one of them as a spectator, and one as a (reluctant or accidental) participant; the first one enveloped me as I sat sipping an espresso on Manchester Piccadilly Station.

A gaggle of women in T-shirts and pink bunny ears invaded the platform like a flashmob or a marketing exercise for a new breakfast cereal called Pink Ears.

Their T-shirts announced that they were on their way to Helen's Hen Do in Edinburgh, and I smiled at the thought of that quiet and sophisticated city being invaded by a gang of Manc rabbits. They lit up the dull platform like a son et lumière and I was happy to note that I wasn't the only one grinning.

The girls weren't smiling, though: one of their number was late and the Edinburgh train was due. The pink ears looked as though they were about to wilt, and they despatched one of their number, wearing what Freddie and the Dreamers used to call Short Shorts, to run down to the station entrance to hunt out the missing Hen, or Bunny.

I'm not joking when I say that the whole of the holding area of Platforms 13 and 14 was gripped by the drama: the two older blokes with their cycle shorts and fold-up bikes, the students on their way to Glastonbury, the family arguing over who should go and buy the chewing gum, the very thin man with the very big briefcase; all of us were watching the screens and watching the ears and hoping that the missing member of the party got there in time, like a real rabbit that just manages to hop across the motorway before the juggernaut thunders by.

I pictured us bursting into applause as she appeared just in time, which, of course, she would have done if this had been a British romantic comedy film. But, sadly, for this site-specific art event, the applause never came. The woman in the shorts ran back to her mates shaking her head just as the train thundered in. They clambered on and I sat there for a while longer in the hope that the holder of the empty seat might still appear, but she never did.

Perhaps it's because I'm a writer, but I imagined whole scenarios for her; left her ticket at home, missed the bus, taxi not turned up. In some fundamental way, we'd all been affected that morning by a real-life drama, a narrative without a conclusion, a site-specific art event that would keep us wondering throughout the rest of the day and into the evening in our various homes as we completed the story in our heads.

The second ritual actually happened the night before, and it was a rawer and colder event, but it still had elements of theatre and drama and comedy and, if you'll pardon the phrase, soaking wet pants.

I'd been to a meeting in Barnsley and my mate, Sean, was giving me a lift home in the pouring rain; we'd dropped off some people at Blacker Hill and we were just trundling past the cricket ground in Wombwell when we saw a huge number of lads standing by the road jumping up and down and shouting.

At first I had no idea what was happening: I thought they were just coming out of the cricket club or maybe they were on their way to a party or maybe they were that phenomenon that strikes fear into
the adult heart, the Gang of Youths on The Street making a Nuisance of Themselves.

Then I noticed that a lot of them had no shirts on, and some had no trousers on, and a lot of them were thin and they looked like Billy Casper in the scene from Kes where they're making him have a shower. It dawned on me what was happening, what ritual I was witnessing, what narrative event I was about to take part in: they wanted Sean, or any passing motorist, to drive into the vast lake of a puddle at the side of the road and splash them.

I'm cautious but Sean isn't. "Come on then, if you want some!" he shouted, although the boys couldn't hear him, and he roared through the puddle sending a tidal wave high into the air and over the lads, who cheered, wetly.

Because I'm cautious and because I'm a writer, I pictured them sneaking home to their mams and getting a good telling off; maybe one mam was the bunny who didn't make it.

Ritual, narrative, drama. Pink ears and wet pants. Makes the world go round, doesn't it?