Sobering, jolting, marrow-shakingly magnificent

Love, etc by Julian Barnes (Jonathan Cape, £15.99)

The new novel by Julian Barnes confirms just how wonderfully he has matured into our finest heavyweight fictionist. What is especially good about Love, etc is the way that its essayistic inclinations - that ingrained tendency of its author to do novels as think pieces about love, death, Frenchness, history, heritage Britain or whatever - are buckled on to more common fictional urges, such as telling stories about people in and out of love, getting on or not and getting old.

The new novel by Julian Barnes confirms just how wonderfully he has matured into our finest heavyweight fictionist. What is especially good about Love, etc is the way that its essayistic inclinations - that ingrained tendency of its author to do novels as think pieces about love, death, Frenchness, history, heritage Britain or whatever - are buckled on to more common fictional urges, such as telling stories about people in and out of love, getting on or not and getting old.

In Love, etc, we meet again the group from Barnes's earlier novel, Talking It Over: sneery motormouth Oliver, who took to wife arty Gillian, ex-wife of his mate, stodgy Stuart. Now, 10 years later, life's little reversals have done their regular worst. Stuart is back from the US, much bewived, terribly rich, a green food mogul, no longer a patronisable dullard.

Oliver, though, is still stuck with his unzipped wordiness, keen to go on patronising Stuart but hampered by his own lack of success. His movie projects are all bummers. He's just a penurious cleverclogs living off his wife's picture-restoring biz and delivering flyers for local takeaways. Gillian and Stuart, surprisingly, get closer again. But is it love? Or rape? Or what?

What haunts them, and us, is the odd incident that ended Talking It Over. Gillian goaded Oliver into hitting her in the face, car keys in hand, in a French village. She knew Stuart was looking and would conclude her new life was no bed of roses. We keep re-envisioning this scene as Oliver saw it in his rear-view mirror, his rétroviseur, as he sped guiltily away.

There's a lot of retrovisuality in the novel. The photo Stuart took of his beloved's bloodied visage has been in his wallet ever since. Its discovery broke up his last American relationship. Discovering the awful truths of this event makes for a set of horrified recognitions and marrow-shaking new perspectives, for which only Aristotle's analysis of Greek tragedy has the words. It's compelling stuff.

As before, these people tell us their stories straight to us, seconded and thirded by other voices - Gillian's French mother, for instance, a wise old bird grown cannier still. She is assisted by Gillian's daughters, Gillian's restorer, Ellie, and Stuart's American ex. This mode of narration engenders a nice jostling, joshing intimacy.

That intimacy grows grimmer as intimations mount of the despair washing about the central trio's lives. "Grown-ups are fuck-ups," is Ellie's refrain. We knew that already, but being made to realise that Barnes and his people really mean it gives this novel its truly sobering, jolting force.

Oliver - magnificently cynical Oliver, the spryly sprung rhythms of his put-downs as awesome as anything Barnes has contrived - loses the will to master life by words. Down and down he sinks, the unhappy object of Stuart's philanthropy (for Gillian's sake): a van-driver, motoring pure greens across the land, in the end turning his face to the wall. It's a morally glum picaresque, if a verbally engrossing one.

Thoughtful chapters accumulate with glooming energy. Barnes can't resist his cataloguing yen on wants (and the lack of gets), on the dire varieties of love, on middle-aged sex, on condoms, on the several ways you might think about Ripeness is All. Wry wisdoms all, carefully laid out in the story's welter of betrayals and surrenders and choices that, Beckett-like, offer only equal miseries.

"Would You Rather?" is one chapter title, celebrating Oliver's recall of a childhood mental exercise. "Would you rather stroll down Oxford Street bollock-naked with a pineapple on your head or marry a member of the Royal Family?" You'd rather neither, of course. But this pair of awful prospects manages to please as it appals by the sheer wit of its address. Which is Barnes's huge attraction. You'd rather - or, at least, I'd rather - be in a Barnes novel, engaging in the tangled terribilia he wields with such power, than almost anywhere else in current British fiction.

The reviewer is professor of English at Oxford University