The Photograph, by Penelope Lively

Salley Vickers finds secrets, lies and irritation in a novel of adultery

In her latest novel, Penelope Lively takes a simple but stark originating event as the catalyst for an exploration of the connections between memory and history, and the capacity of the past to radically affect the present. A widower discovers a photograph of his beautiful dead wife, which indicates that she once had an affair with her brother-in-law. The husband, Glyn, is a professor of landscape history, a subject that lends itself nicely to metaphor. His expertise, in obsessively tracking down the tell-tale signs that reveal the "truth" of the past, informs the novel.

But, as contemporary fiction has taught us, the past, like the truth, is a very dark horse. As we should also know, snoopers never find good for themselves. The novel is told from the standpoint of various characters, all of whom have played some role in the old affair.

That this affair turns out to be a very banal event is part of the point. Everyone, once involved, gets it out of proportion – but that, of course, is a feature of human psychology. What the novel explores is not only that we often do not know those whom we live closest to, but that we largely choose to ignore them in pursuit of our own selfish objectives. Our indignation at discovering undisclosed elements to their lives is pathetic and naive.

Glyn's first move, on discovering the photograph, is to show it to his dead wife's sister – an action that precipitates the break-up of her marriage.

Glyn's self-serving need to share his situation with his sister-in-law Elaine – to ensure he will have a companion in being cuckolded – is well observed. It is a petty, but typical, act of unthinking insensitivity, which fits with the larger picture of the man who gradually emerges.

Elaine herself is no moral oil-painting. She has forged a successful career as a landscape gardener and lives in a state of mutinous annoyance with her husband, Nick. But Nick, too, is a bit of an ass: a dilettante, who had learned to batten on his wife's superior maturity to run his life, and on her earnings to replace his wine and car.

Their daughter, Polly, is a thirtysomething website designer who runs her life on pragmatic lines but wants her parents preserved as a fixed point of childhood nostalgia. Understandably, she is dismayed when their marriage of 40 years is thrown into disarray and, as a consequence, her father, in a neat cliché reversal, becomes an embarrassing social hindrance in her London flat.

My difficulty with this book was that I found few of the characters sympathetic. Not that all must charm, but they must win our involvement and too often I felt that, for the author, the principal dynamic was irritation rather than understanding. Easily the most compelling character is the absent Kath, whom we meet in recurring complex images in the minds of those who knew her.

Here, too, expectation is reversed. Far from being a contemporary Rebecca, or the adulteress of Glyn's suspicions, Kath is revealed as a poignant figure whose gift is to reflect life's joy for others but who is tragically incapable of feeling it for herself. Her suicide is the consequence of disappointment, not in any affair, but in the limitations of those who purported to love her most. They discover her frailty, and their own capacity to destroy, too late.

There are two survivors who redeem the rest. Oliver, Nick's business partner, and Mary, a sculptress, have seen Kath not through the lens of narcissistic need but purely as herself. Neither has a sexual or familial role in Kath's life, as if Lively is saying that we are most endangered by those who seem most to promise love – an acute, if dispiriting, observation.

Salley Vickers' novel 'Instances of the Number 3' is published by Fourth Estate