Here's a Hallmark card for all those who have loved and lost: a mushy memorial to a brief encounter in the Midwest. One enchanted afternoon, across her Iowa farmyard, Francesca Johnson sees a stranger: ``his eyes looked directly at her, and she felt something jump inside.'' He reminds her of a gazelle, make that a leopard or, better yet, ``some star creature who had drafted in on the tail of a comet,'' for obviously he's come ``a long way, across more than miles.'' In fact, 52-year-old National Geographic photographer Robert Kincaid has driven from Washington State to shoot the covered bridges of Madison County; what wonderful luck for these soon-to-be-lovers, this hot August of 1965, that 45-year- old Francesca's husband Richard, along with their two children, is at a state fair for a week. The Italian Francesca, who married Richard 20 years before in Naples but now feels ``compromised and alone,'' asks the equally lonely, equally sensitive Robert to dinner. That's Day One; on Day Two, they fall in love; and when they make whoopee, it's as much spiritual as physical, what with Robert whispering, ``I am the highway and a peregrine and all the sails that ever went to sea.'' On Day Four, their last together, Francesca announces she must stay with her family, but their bond is forever: As Robert says, ``in a universe of ambiguity, this kind of certainty comes only once.'' Looking back years later, Francesca concludes that undying, romantic, extramarital love is compatible with family values. That conclusion should sit well with the target audience; for as fake and pretentious as it is, this first novel is based on hard-nosed commercial calculations. The publisher, promising a big push, clearly expects its silly goose to lay a golden egg, and, who knows, maybe it will.