All aboard the gravy train; Don't expect unbiased reporting from Edinburgh. Peter Guttridge found the bribery beginning before the critics even arrived there
Where's Wally? It's almost 10 in the morning at King's Cross station and the famously elusive children's book character is nowhere to be found. Just doing his job, you might think - but no, this is serious. He's going to be needed shortly for a photocall with his chums Wenda and Wizard Whitebeard. Wenda's leaning on a luggage trolley and the magician is loitering over by the departures board, but no one is taking a blind bit of notice, as if women wearing red-striped bobble-hats in the middle of summer and men in full-length red dresses and long white beards are a daily occurrence.

Wally's not the only one who can't be found. Also hidden in the crowd on the concourse are dozens of writers, publishers, journalists and PR people waiting for the platform announcement so they can board the InterCity 225 that will take them in first-class comfort to this year's Edinburgh Book Festival.

Every second year the Book Festival sets up enormous tents in Charlotte Square, and does its bit for the fever that grips Edinburgh once the Fringe, the Film Festival and the Festival proper are up and running. This year the book festival, which runs until 28 August, features more than 200 authors from around the world, and over 400 events, half of them free. Germaine Greer, Terry Pratchett, Edna O'Brien and Garrison Keillor will all be there.

Depending on your point of view, four hours on a train in the company of a bunch of writers, with a free supply of all the British Rail sandwiches you can eat, may or may not count as a good time. With free booze also on tap, friendships that spring up by Peterborough could become feuds by York. The history of drunkenness in literature teaches us that it's the poets you have to watch. There are none on this train, but personally I've always thought children's authors can also be pretty tricky.

The train pulls out on time, with Wally and his chums - in real life, editors from Walker Books - safely on board. The editors look uncannily like the characters they are playing. Was it part of their job specification?

Distinguishing writers from publishers and various freeloaders is no easier in the two carriages of the train reserved for the Book Festival than it was on the concourse. And is that man with the clearly false Tsar- of-all-the-Russias beard a writer or another character from a book? A number of interlopers strayed into the carriage at the off and have stayed for the free nosh. One is an elderly lady who is a dead ringer for the woman who disappears off the train in The Lady Vanishes. Trains feature frequently in spy and thriller films, but with notable exceptions don't figure largely in literature.

When asked about this, one publisher, best left anonymous, starts to recite the Auden poem from the film about the night mail. His rhythm keeps impressively to the clack of the train wheels but he rather spoils the effect by mixing in lines from the Auden poem that featured in Four Weddings and a Funeral. Of course, by then the wine and the whisky are flowing.

Everybody starts to loosen up between Peterborough and York. Nothing too bawdy, of course, and far less rowdy than most commuter-train buffet cars of a Friday evening. "No one's bonking yet," a woman from Sky TV notes. But the aisles are clogged and the noise level has risen, making life difficult for those who pointedly keep their noses stuck in books.

PRs ferry journalists and film crews between celebrity authors. Marsha Hunt is most in demand. She's travelling up for the announcement of the first winner of the Saga Prize, which she set up to encourage black writers in Britain. She's travelling with the winner, 26-year-old first-time novelist Diran Adebayo, an Oxford-educated print and TV journalist. "I actually had the idea for the prize when I was at the Edinburgh Festival with my daughter Karis last year," Hunt says. "So it's very appropriate that the first winner should be announced there."

Journalist Yvonne Roberts, whose first novel Every Woman Deserves An Adventure comes out in paperback this month, is more used to interviewing than to being interviewed. "I feel a fraud," she says. "I've only had one novel published and I'm being asked my opinions about writing." She is taking part in a debate about "bad girls" at the festival and is furiously reading the latest books of fellow panellists Victoria Glendinning and Jane Urquhart to see if they have anything in common.

"This is the best train I've been on," says David Wood of Jackanory and Playaway fame, who is proudly showing his new pop-up book of magic to all and sundry. "When I did a round-Britain train tour with other authors for a children's book festival, they didn't actually allow us to travel on the train for logistical reasons. We'd fly and then hop on the train just outside the station we were due to perform at."

Two children in the carriage are particularly taken with the book. They are travelling with their parents, who won a competition in a local paper for a weekend at the Book Festival. For the husband, the highlight of the weekend has already happened: he met Marsha Hunt. The children are listening to cassettes. A group of publishers sit around a table littered with half-empty cartons of soft drink, discussing the phenomenal success of this area of publishing.

"Maybe it's time for a dedicated radio station to tap the market," one of them says. "Wall-to-wall novels, short stories, children's stuff and plays. We can call it the Home Service."

By Newcastle the old lady from The Lady Vanishes has mysteriously disappeared. Well, OK, she got off at York. People who have used the restaurant car next door return, cheerfully announcing it is indeed better to travel than to arrive, but arrival isn't far away as the train goes past Berwick and along the shores of Scotland's picturesque east coast. There's supposed to be another photocall when the train reaches Edinburgh, but a few minutes outside the station it clicks that this train will be stopping there for just two minutes before going on to Glasgow.

As the train pulls into platform four on Waverley Station - where a stern- looking laird with a handlebar moustache and a kilt is conveniently providing local colour - nobody seems keen to get off. When they finally do, it's all a bit of a scramble, with writers and their luggage abruptly disgorged onto the platform. The train pulls out for Glasgow and it's clear there's only one question in Wenda's mind as she looks forlornly after it. Where's Wally?