John and Jill at the end of the rainbow

Theirs was the love story of the decade, a love that conquered all odds and made a nation believe that fairytales could come true," declared yesterday's Sun, in a trembling, three-page exclusive. "But today, the love lies bleeding, shot through the heart by the harsh realities of life."

What could have prompted this purple outpouring of tender emotion? Courtney Love finally giving up on life without Kurt? Twenty things you didn't know about Romeo and Juliet? News of Charles and Di's divorce?

Nothing, alas, so rock 'n' roll, so bloody, so constitutional. For this is the story of John and Jill, and the end of a more ordinary romance. He, 38, came from Barnet and grew up in Hertfordshire. Failed to get into Oxford, was known to wear red sweaters. Confessed that things he enjoyed including making the tea and getting the car serviced. Didn't have a chiselled jaw.

She, 35, grew up in a village near Doncaster, joined the Church Girls' Brigade, went to Hull University. Was blonde, but only 5ft tall. They met at work in 1983, eventually moved in together in 1991. And now, after a 12-year, on-off-on relationship, they are splitting up in the dullest possible way. There are no children, no expensive settlements, no secret lovers and, apparently, no acrimony. "There's no bitterness, no one else is involved," an unnamed friend told the Sun. No Hollywood studio is bidding for rights. Tom Cruise and Demi Moore are not up for the roles.

But since the Nineties is the decade when the Royal family suffered romantic implosion, the decade in which marriage has been declared dead, we Brits have been desperate for love, for romance, for happy endings. The John and Jill story, of a love that conquered all, was our last hope. Their book, Some Other Rainbow, outsold heaving Catherine Cookson and humping Jilly Cooper.

And in some way theirs was an amazing story, involving chains and dungeons and cockroaches and rats. Of unimaginable suffering. Of a campaigner who wouldn't give up. Of hope undimmed and the triumph of freedom. The fact that John and Jill were just an ordinary couple made it even easier for us to identify with their story. In the words of John Waite, cousin to John's fellow hostage Terry - who received the news of the couple's split as a "bombshell" - "All hostages are ordinary people who have been made extraordinary by their experience."

Now the last great romance - possibly the age of romance - is over and the big question is "Why?" Or, perhaps, "Why?!"

There are various possibilities. Relentless will they/won't they pressure from public and press. The sad, ordinary, fizzling out of a relationship. Or the "shadow of Beirut" theory, handily romantic and advocated by the Sun.

Being kidnapped for five years is, of course, a profoundly traumatising experience. "Former hostages are likely to experience periods of anxiety and depressive disorders," says Dr James Thompson, director of the Traumatic Stress clinic at Middlesex Hospital. "Typically they report that relationships, in particularly the sex side, suffers. One would expect John McCarthy to be used to more solitude, meditation and fantasising than is normal so it will make it harder for him to slide into a normal relationship."

This view is confirmed in Some Other Rainbow: "In the drabness of the cell, the picture of her smiling face was a constant source of joy... During the long nights I would remake plans for my future with Jill. I would spend hours planning what sort of place we would have, the number of rooms, the location, even bits of furniture... Once more I had the determination to carry on another day." Meanwhile, Jill was trapped in tabloid hell.

Since his release, John has said: "It's no good having children if you are not in a state to look after them." On the first anniversary of his release, the couple sent on open letter to the press which described getting to know the world again as a "daunting task". John's fellow hostage and bosom buddy Brian Keenan, sensibly, opted to marry his nurse.

Yet friends and colleagues describe John and Jill as remarkably unaffected by the press (they are both, after all, journalists) and the trauma of Beirut. "Very charming guy, funny, gentle, unassuming, in pretty good shape," says Alasdair Palmer, co-producer of Hostages, the Granada drama- documentary account of their story from which the couple later disassociated themselves. And Jill? "Intelligent, focused, strong-willed, courageous, seemed no different before and after his release."

Romantics will be further disappointed to learn that, from the outside, The End looks ordinary, ordinary, ordinary. John and Jill should have fizzled out years ago. Though they had been together for three years prior to his kidnap in April 1986, they had not moved in together. Working in Beirut prior to his kidnap, John was, according to one report, known to be something of a ladies' man. His "friend Jill" is mentioned only once in Brian Keenan's book An Evil Cradling.

And the heroine? Horribly pragmatic about the relationship, all along. As she said in interviews to publicise the Free John McCarthy Campaign: "A future with John had begun to seem more like fantasy as time went on. I hoped he would still love me. But what if he didn't? I didn't want him to feel obligated. I didn't want to put pressure on John, to make him feel that he had no choice but to come back to me." Says John Waite: "Jill never made any pretence to me that John was necessarily the love of her life. She was never a one-man, lovelorn lady waiting for her lost love. And she was not a hermit when John was away." Their reunion, in August 1991, was muted, even stiff.

It seems that she began the campaign not as a grand romantic gesture but from a sense of ordinary justice, when press attention had hitherto been focused exclusively on Terry Waite. Though she was often pushed into the limelight, as a journalist she knew that the fevered imaginings of the press was an effective tactic.

The least explicable aspect of the John and Jill story is their book - all blushing sunsets on the cover, though no gazing into each other's eyes - which didn't allow them to fade out of the public eye. Well, it certainly paid the rent for a few years. But, more importantly, according to John Waite, it was an attempt to work through the experience of the past 10 years.

They have, it seems, at last worked that experience through. Sensible to the last, John and Jill have worked out the ending of the fairy tale. They didn't want to be together after all. They will probably live, separately, happily ever after.