IT'S 1965. A 52-year-old National Geographic photographer named Robert Kincaid drives his pick-up truck to the porch of an Iowa farmhouse and asks 45-year-old Francesca Johnson, an Italian war-bride whose husband and children are away at an agricultural show, for directions to a bridge. Within 48 hours Robert and Francesca are in love, in the kitchen and in a clinch. Another 48 hours and they are separated forever. It's 1993. Unlikely as it seems, The Bridges of Madison County, the 171-page novel summarised above, has become the most talked about book in the United States. It has rocketed first-time novelist Robert James Waller, a 53-year-old professor of management at the University of Northern Iowa, to fame, fortune and a special place in the hearts of romantics everywhere. It has been on The New York Times bestseller list for more than a year - unheard of for a hardback - and has allowed respected authors like Tom Clancy and John Grisham to occupy the number one spot only fleetingly, before grabbing it back again. Publisher Warner Books, which scheduled a modest 29,000 print-run when the book was first released in April 1992 will have shipped more than four million copies by the end of this year. Steven Spielberg's Amblin Entertainment has bought the film rights andrumour has it Robert Redford wants to play the lead, though Clint Eastwood has also been mentioned as a possible candidate to play Kincaid. Public demand for the book has been so unstinting that Waller who, like his hero Kincaid, can strum a few tunes on a guitar, has recorded an album, The Ballads of Madison County. One song is a four-minute synopsis of the book. The only song Kincaid can play right through is Bob Dylan's Girl From the North Country. According to early reviews of the album, Waller's repertoire is little bigger. The author is also a photographer, and has recently taken pictures of the now famous covered bridges of Madison Country for a 1994 calendar. Waller's second novel, Slow Waltz atCedar Bend, about a professor who falls in love with a colleague's wife and writes a book called The Bridges of Madison County, is about to hit the book shelves in the US. It, too, has been optioned by Amblin. 'I'm on a galloping horse, and I'm not gettingoff until it drops,' says Waller. However, the mainstream media has given it mixed reviews. 'Like Coke that's been opened a while ago: sweet but flat' and 'pornography for middle-aged women', sniped the Los Angeles Times. 'A rather cynical, content-free packaging of loss and longing,' saidUS News and World Report. But away from the big cities they took another view. 'As perfect as a pear,' said a reviewer in Florida. 'I would give my life for an hour of their love,' said another in Missouri. A journalist from the Seattle Times rang the library to see if she could find the issue of National Geographic in which the bridge photographs appeared. There isn't one, but she hasn't been the only person to make the inquiry. The book has tapped into twin desires in American readers: the desire for passionate love and the desire for a happy family life. Francesca writes a letter to her children explaining that only the memory of her love affair for a lean Levi's-wearing, weatherbeaten photographer kept her on the farm in Iowa for all those years. The kind of affair that helps you fulfil your responsibilities is all right by middle America. And it hasn't hurt book sales that the two protagonists are older. Kincaid finds younger women unattractive because they lack the 'intelligence and passion born of living'. Nor do the obvious parallels with the lean Levi's-wearing weatherbeaten Waller's life seem to put people off. 'People ring me and thank me for being,' says Waller. 'Lots of them want to tell me about affairs they've had which are similar. I got a call froman 85-year-old man who was reading it to his blind wife. I've had a 56-year-old Vietnam veteran bawling on the phone to me. It's been amazing.'' It is not unusual for Waller to look out his window and see people picking leaves from his tree and pressing them into the book. Significantly, one of the first groups to fall in love with the novel was booksellers. Warner sent them early copies and urged them to read it - not an original ploy, but it worked. They began 'handselling' it - not letting customers out of their shops without looking at it. 'I have read the book seven times,' said Beth Robbins, a bookstore owner in California. 'First I changed my order from five to 50 then to 100. And this is a teeny little bookstore. A maximum order here is 15.' A shop in Sarasota, Florida, sold 1,200 copies and offered all buyers their money back if they weren't satisfied. It didn't pay out much. At the annual booksellers' convention in Miami last May, Waller's book signings generated long lines. 'They just want to shake my hand and thank me for paying their rent this year,' he says. Winterset, the setting for the novel, has not escaped the mania. Tourists regularly stop and ask for directions to the bridge that Francesca showed Kincaid; they inquire at which table in the cafe the two sat and they call in on the chamber of commerce andbuy souvenirs. Residents don't mind. It's good for business and they're expecting a big crowd at Covered Bridge Weekend next month. Meanwhile Waller takes it all in his stride. Married for 31 years to Georgia Ann, whom he met in college, and still living in the same A-frame chalet in the woods in Northern lowa, his only concessions to fame are an unlisted number, a new security system and the abandonment of his academic career. He's under contract for two more books to Warner, but no more love stories. Sometimes he feels uncomfortable about the enormity of sentiment his book has generated. In Bridges' preface he notes: 'Where great passion leaves off and mawkishness begins, I'm not sure.' He readily admits it only took him two weeks to write the book. But he bristles at the suggestion that he's an overnight success. 'It took me two weeks,' he says. 'And 50 years.' ROBERT & FRANCESCA: IN THEIR OWN WORDS With her face buried in his neck and her skin against his, she could smell rivers and woodsmoke, could hear steaming trains chuffing out of winter stations in long ago nighttimes, could see travellers in black robes moving steadily along frozen rivers and through summer meadows, beating their way toward the end of things. He noticed all of her. He could have walked out on this earlier, could still walk. Rationality shrieked at him. 'Let it go, Kincaid, get back on the road. Shoot the bridges. Go to India. Stop in Bangkok on the way and look up the silk merchant's daughter who knows every ecstatic secret the old ways can teach. Swim naked with her a dawn in jungle pools and listen to her scream as you turn her inside out at twilight' - the voice was hissing now - 'it's outrunning you.'