John Walsh on Monday: Lost in the menacing streets of Ledbury

SATURDAY NIGHT in Ledbury, Herefordshire. The handsome old market town has gone all frisky for its annual poetry jamboree. Though established only three years ago, the Ledbury Poetry Festival has grown like a bolted Parnassian cauliflower until it has taken over the town where John Masefield was born. It has, to vary the metaphor, carved such a distinct niche for itself in the huge wall of seasonal literary events that, if you ever think of the words "poetry festival", it is the word "Ledbury" you think of next. And it reaches beyond the ambit of verse readings and versifying workshops to become a celebration of international cultural jollity.

Tonight there is a whiff of the passeggiata and the carnivale hanging over the cobbled streets. The city fathers have closed off all the roads leading into the market square, and crowds mill about, eating handfuls of seared meat, drinking pints from plastic cups and swaying, in that slightly embarrassed English way, to some unusual rhythms on the night breeze. A beer tap has been set up under the spectacular monochrome Tudor- beamed Market House where, legend has it, W H Auden married Thomas Mann's daughter Erika back in the Thirties to get her a safe passage out of the Nazi grip.

The house looms over the square like a chequerboard canopy over the revels. Alongside the beer drinkers, a gang of folk musicians with flutes and violins has been joined by a dozen local amateurs, stroking simple chords on guitars or harmonising a little uncertainly with the vocals; it's the sonic equivalent of a line-dancing class but it sounds OK.

Next door, arrayed on the open side of a huge lorry trailer, a salsa band has been tuning up, nine of them and a singer; he is bulky, swarthy and waves his hand rousingly overhead as he sings but is (I'd say) the only echt Latino in this bunch; the brass section is cool and shaven-headed, looking, as many modern jazz musicians do, like genial ex-convicts who handle a trombone slide as though racking a pump-action shotgun.

I am here with my three children and their nanny to introduce some poets, ask them searching questions ("Does your use of the anapaestic tetrameter imply that you aspire to the Byronic? Or do you like the way it sounds?") and play badminton with the children in the garden of the lovely house we've got. It's the wing of a 16th-century oak-timbered granary outside Much Marcle, a charming village with a name redolent of Miss Marple and all the cosy paraphernalia of Agatha Christie's shut-off world - although its name sounds a faint bell at the back of my memory that I can't quite place.

No matter: I am a soul in bliss. The children love the place. There's a Big Scary Bull in the neighbouring field to give them a frisson of fear.

The family dog has formed a Sapphic crush on a mirror-image labrador called Tinkerbell.

The poetry events have gone well (apart from the moment when I co-opted the audience to beg Fleur Adcock to read from her much-quoted early poem "Against Coupling" and she flatly refused). In my hand is a pint of authentic hand-pulled, burnt-amber-coloured foaming local quaff, a beer so sweet it should have dimples and a pigtail. The air is fizzing with the flavours of barbecue and hot-dog stand. Every 10 yards or so you meet someone from the metropolitan literary carousel - and look, here's an old friend, my son's ex-nanny with her tiny daughter, and what a laughing bourgeois cabal we must seem under the benign un-darkening sky. Not least of the attractions is the local beauty, a six-foot bombshell in blue silk harem pants and tumbling cascades of chestnut hair, dancing a lithe and fluttery Oriental solo of her own devising in front of the salsa band, while less innocent eyes than my own traverse her fluent body as though watching a vertical match.

"I'll be back soon," I tell the children. "Don't wander off. I'm going to stroll for 10 minutes to see what's happening." Fifteen minutes later, deep in conversation with a belligerent northern poet, I notice the chestnut bombshell striding past on her way home. Oh, the music must have stopped. I look back and see, yes, the crowds are dispersing, so I say cheerio and head back to the family.

They've gone. Of the two nannies and four children there's no sign.

I walked around, looking into faces, catching near-miss sightings of the seven and three-year-old among the shorter revellers, but they're not them. My kids and their attendant handmaids have disappeared into the thick night air.

It was the start of a classic nightmare that transformed the smiling face of the countryside, and this happy carnival. Without the tumble of salsa music, things suddenly seemed a little ragged and unwelcoming, like being at a party where you suddenly realise you don't know anyone.

I walked up and down, starting to hate people for not being the only people I wanted to see. I ducked this way and that, to the hospital's noble gates, the war memorial with its oddly Biggles-ish tile-painted airman, to the Pig Roast roadside stall. I looked in the shops, the Feathers and the Six Bells. Nothing. An old, all-too-familiar terror, from the earliest days of fatherhood, began to tighten by a few ratchets in my heart.

They were nowhere. My children were lost and gone, maybe for ever, became the disappeared, Max in his Fauntleroy curls, Sophie in her sensible butterfly hairgrips, not-quite-four Clementine in her pink cardigan, buttoned against the night chill. They'd all vanished into the Ledbury night as surely, and as oddly, as the schoolgirls in Picnic at Hanging Rock. I had to save them.

Reasoning that someone must have driven them home, I found the car, took a massive detour around the town (the streets were blocked for the party, remember) and headed for Much Marcle. It came on to rain. Gusts of water lashed the car like North Sea waves. Psycho-like, the wipers slapped accusingly back and forth. I thought of Clementine standing heedlessly drenched by a locked front door, hours after her bedtime, her cardigan visibly shrinking.

There was no one there. The lovely grain house was eerily deserted. I had to go back. On the way back to town, the significance of the village's name detached itself from the back of my memory and settled at the front. Much Marcle was where Fred West was born.

Back in Ledbury, the rained-on revellers looked more sinister than before. As I crashed through knots of dancers, desperate for a clue to my children's whereabouts, the faces seemed frankly hostile. At the Pig Roast stand, I realise there was a whole roasted porker lying there on a dais, its flesh carved and mutilated, its head untouched and smiling painfully. I who had, two hours before, longed for some crackling, could now see only its cosmic pain, its exploited corpse.

Poetry, hah. In very little time, my serene and lyric-pastoral mood had changed to an epic revenger's-tragedy snarl. The people looked at my ravaged face with a not-you-again scowl. I asked a St John Ambulance man where missing persons went. He recommended seizing a microphone from the bald salsa merchants and making an announcement, but I was afraid I might choke.

How could I stand there, bulging-eyed and desperate under the sniper's rainy sky and shout, with the amplification of despair, "I've lost my children"?

I found them at last, near the dark shadow of the Market House, being fed orange and biscuits by the nice festival people, while helpers were dispatched to look for me in the lowest pubs of the town. They had waited too long for me, then gone on an unscheduled night-time shopping trip. They'll be sorry to leave this town, and so will I. But I know this much: you have no idea how fast and how radically a place can seem to change its nature, when seen through the mad staring eyes of the imagination.

YOU KNOW of John Calder, I'm sure, the veteran publisher and a man of legendary independence and firm resolve. He celebrates this year a half- century of putting good writing into hard covers and taking the consequences. He has in the process published some of the century's greatest writers: Beckett (who used to sign his letters to Calder "With failing words my unfailing affection"), Henry Miller, Borges, Artaud, William Burroughs, Alain Robbe-Grillet, Pirandello - his most plausible boast is that he's had more Nobel prize-winners on his books (18 last count) than anyone else in the heavy-lunching trade. And naturally he's been embroiled in controversy over the years. He was all set to publish Lolita in England in the early Fifties, but its author, Vladimir Nabokov, was suspicious of Calder's supposed communist leanings. Calder endured the flak that attended the birth of Tropic of Cancer and its sequel and was taken to court after Cyril Black, the Tory MP for Wimbledon, tried to get Last Exit to Brooklyn banned.

Calder has picked up a lot of enemies - including Nigel Nicolson (who was deselected as Tory MP for Bournemouth when his constituents decided they didn't approve of his being co-publisher of Lolita), William Rees- Mogg and Lord Neill, the former brief Patrick Neill. And many of his surviving enemies are now being invited to the Riverside Studios in Hammersmith to see Damned Publishing, devised by Calder but extemporised by the cast - a script, you see, would have been too libellous. The show runs for six nights from 20 July. The other striking innovation is that some people who appear in the show may also be in the audience. Calder has invited 30 people each night who have a bearing on his career - but whether for good or ill, they'll have to go along and find out.