The mission Maggie O'Farrell sets out to discover if there is such thing as a free lunch but has a very hairy experience ...

oon: the lunching hour begins and

I am entering Quo Vadis, the Soho

restaurant backed by artist Damien Hirst. I reckon he can afford it. As I approach the desk, the two women behind it part their lips in what, in some circles, would pass as a smile. "Hello," I say, "I'd like to have lunch, please. For free." There is a pause. The smiles disappear. "Is that possible?" I ask. "No." They look at me as if I'm a bit of something that's fallen off one of Damien's art works. "No," they say again, just in case I didn't understand.

Nearby, at Sir Terence Conran's Mezzo, the man's reply strikes me as bizarre: "You're wearing trainers." We look down at my feet together. "Does that mean that if I wasn't wearing trainers I could get a free lunch?" "We're booked up," he says. "What, for free lunches?" "You're wearing trainers," he says again. The man's obviously on some strange autopilot, so I leave.

I try a few other places: the man in trendy Bar Italia pretends he's lost his grasp of the English language; and the nice Canadian boy who's stacking the fridges of the sandwich store Pret a Manger just looks frightened.

1pm: I loiter with intent outside the Groucho Club, the media hangout. A man in a suit gets out of a cab. "Hey!" I greet him, wondering why I suddenly sound American, "would you mind buying me lunch?" He stops, his fingers plucking nervously at his mobile-phone aerial, and makes the noise "Hhrrrrggh?" I repeat my request. "Do I know you?" he asks. "No," I reply, and he runs away, throwing himself through the Groucho's doors. My stomach emits a growl the type of which is usually heard only in the proximity of Longleat.

1.30pm: food is now a matter of urgency. I decide that crashing a corporate gathering is my only option. In what I am convinced is a matter of divine psychicness, the man on reception at the Sony building says, "Have you come for the lunch?" I sign for a security pass and float down the stairs wondering if I should marry him. But plans for our future are rudely interrupted when I see that the room is filled with men networking earnestly, holding glasses of mineral water, and the only edible things around are a few bowls of crisps. I scoff down as many as I can and ruminate over how similar the words "lunch" and "launch" sound. A woman cannot live by crisps alone. I leave, without a backward glance for the reception man.

Outside, Soho's Golden Square is filled with people eating sandwiches. I approach two women who are sunning the tops of their Wonderbra-enhanced chests. "Hi. Do you have any food you could give me?" They stop, mid-chew, and stare at me. Then they resume their conversation.

As a last resort, I sidle up to a lone man who has inexplicably rolled up the bottoms of his suit trousers. Success! He produces a sandwich - a fresh mozzarella and tomato nirvana of a free lunch. I am so close, I nearly have it in my hand when he says: "Only if I can touch your hair." I decide that a) he's a weirdo and b) hair-touching constitutes payment. Decline, and stalk off to the cashpoint