So he published it himself.

No one could say Iqbal Ahmed isn't resourceful. He's turned his hand to all kinds of jobs since he came to London ten years ago, at the age of 26. First he sold newspapers and magazines from a corner shop in South End Green, on the edge of Hampstead Heath. Later he worked at Waterstone's, selling books. At the moment, on Friday, Saturday and Sunday evenings he's a commissionaire at the Swiss Cottage Marriott.

Many thousands of people in London are doing the same sort of thing: newcomers, making their way through unknown territory, finding temporary homes, working long hours for little money, missing their families back home, and thinking in other languages on buses and bikes. While they are still just anxious-looking aliens whose bodies seem surprised by the thick anoraks and scarves they're wearing, native Londoners hardly see them - as if their foreignness were a fairytale cloak of invisibility.

Does it hurt to be ignored? If it does, new immigrants have too many other worries to dwell on it. Later, once they've settled in and found more permanent work and the random friends that newcomers muster, most try and forget that grinding, lonely start. It's a little piece of history that almost always gets lost.

This is the history that Iqbal Ahmed has made it his business to record. His book is about the London of newcomers, the subject Monica Ali tackled in her award-winning novel Brick Lane: the city that native Londoners never see.

Sorrows of the Moon: A Journey Through London is short, elegant and sometimes darkly funny. Yet its focus on the pariah status and loneliness of immigrants makes unsettling reading for anyone who has always lived here. There are no heart-warming tales about Cockney jollity or lending cups of sugar to new neighbours.

The London Iqbal portrays is merciless; and Londoners, dealing with the doormen, cab-drivers and cigarette salesmen they share the streets with but don't see, can be a mean-spirited lot. ("I once made the mistake of asking a woman whom I saw often in the corner shop, if I could join her at a table in a café in Hampstead. The woman seemed puzzled and looked pointedly at the empty tables. I realised my folly and rushed to a table at the far end of the café.")

His own life isn't at the centre of the book (although he rather reluctantly puts a little of it in his tenth and final chapter, "The False Reputation of Hampstead"). He feels easier with invisibility: most of his stories are about chance acquaintances - other immigrants, settling down in different parts of town: all riffs on the same theme of displaced people losing both what they have left behind and what they've come to.

The man I meet in Dominique's café on South End Green, on a sunny winter's day with a Salvation Army brass band playing carols outside, is in his thirties, not tall, poised, and neatly dressed in a wine-coloured jersey. He has a shy smile and strong features. He's happier asking questions than giving answers. And he may be the only genuine intellectual I've ever met in Hampstead. He lives in books (real literary books, that is - he can't believe the people he's seen in Waterstone's, buying books about Big Brother).The literary influences he reels off are Borges, VS Naipaul, Nabokov and Proust. His title is a borrowing from Baudelaire.

The waiters know him; they laugh encouragingly when they see me reading his book.

There's every reason to be happy. The book he worked on for nine months and finished in May was in the bookshops by September. Self-publishing, in the age of easy consumer choice, turns out to have moved on from the vanity presses of the past. Iqbal found an editor to check the manuscripts for mistakes. He designed the jacket - women in saris in Trafalgar Square on a yellow background - and picked the paper and the typeface. ("I knew how it should look from my time at Waterstones," he says.) It looks professional; booksellers have happily found it space in their stores.

Iqbal has also found literary friends. The novelist Deborah Moggach read the book and became a fan. The publisher and agent Geraldine Cooke is singing Iqbal's praises at book soirees. He's been interviewed in the Camden Journal and reviewed (favourably) in the Times Literary Supplement. He's hoping for a review in the London Review of Books, where he's written in the past. And he's sold 800 copies. By next month he will have broken even ("not that the money was what mattered").

Iqbal is writing a second book now. It will be set outside London. He has already started travelling to Oxford and Cambridge and beyond to gather material (and wondering whether you can hope to write a good book until you've tried it three or four times; or whether you should consider each book you write your last word and make it as perfect as possible).

Meanwhile, he's sent a copy of his first book to his parents in Kashmir, who have a family business but can't read English. He's sure someone has translated parts of it for his mother. When, during one of his weekly phone calls home, he told her he was working on another book, she answered, quick as a flash: "Make this one better."

Slices of London: e-mail Urban Fox here

What a delightful article. I am an English woman living in Western Massachusetts in a small college town. Recently I spent a month in England - travelling round to rural places - but mostly in London. While in London I was struck by the huge variety of new faces from our former Empire. We had all grown used to West Indian and Indian accents and appearances. But now I felt the presence of the whole Middle East and all the "stans". I sometimes watched them as they swept trash from the pavements, or elegantly served food in restaurants, and wondered how they felt about us. I shall do my utmost to get hold of the book. Best wishes, Jane Poncia