BOOK REVIEW / Dead soldiers, broken hearts: 'A Very Long Engagement' - Sebastien Japrisot Tr. Linda Coverdale: Harvill, 9.99 pounds

THE current controversy over the execution of shell-shocked soldiers accused of cowardice bears ample testimony to the First World War's continuing power to inflict pain and grief 75 years after the Armistice. Here is timely evidence of the grip that the War to End All Wars still exerts on artists, particularly writers. Sebastien Japrisot is described as 'France's master crime-writer', but although A Very Long Engagement deals with crimes against humanity, it is not a crime novel in the orthodox sense. It is, however, a first-rate mystery, and a love story to break your heart.

On a freezing night in January 1917 five French soldiers are pushed into no man's land, their hands bound. They have been court martialled for self-inflicted wounds, and this uniquely cynical punishment is being meted out pour encourager les autres. A couple of days later, after the front line has moved on, the bodies of five French soldiers are discovered by a passing Canadian and buried in a shell crater. The youngest of the five unfortunates, a gangly fisherman called Jean Etchevery, known to his family as Manech and to his mates as Cornflower, had a fiancee, Mathilde. ('Engagement' in the French title is unambiguously marital - fiancailles - whereas by one of those little flukes of translation it acquires a complete extra meaning in English.)

Like millions of other women, Mathilde is notified of Manech's death 'in action', and sets to grieving. But something about his last letter to her, written hours before he was set loose in the snow to die, gives her a little spark of hope. Then a letter two years later from a Sergeant Esperanza, who was in command of the squad detailed to escort the prisoners up to the lines, sets her off on what would seem to be a wild-goose chase - to find what really happened to her fiance, and even, madly, to confirm that he survived. Despite losing the use of her legs in a childhood accident, the wheelchair-bound Mathilde is indomitable in the pursuit of the man who so briefly but so exquisitely awakened her passion. The effects of her quest spread out like ripples on a pond, awakening memories in a succession of anciens combattants, grieving women and others only peripherally involved. Letters, notes of conversations, half-remembered names, crumpled photographs - all are lovingly placed in the wooden box that serves as a symbolic coffin for her lost man, until, seven years on, she finally discovered what really happened on that terrible night.

It would be unfair to say more, save that the narrative is brilliantly complex and beguiling, and the climax devastating. Rumours are triumphantly confirmed, while certainties are ruthlessly disposed of. Every detail in the patchwork has its relevance, and the reader who fails to give the book full concentration will soon be floundering. Like Richard Burns' Dance for the Moon, A Very Long Engagement is a contemporary novel that takes one small, banal (relatively speaking) event from all those years ago and turns it into art without cheating or cheapening.

My own grandfather disappeared into the mud of Loos in 1915, 32 years before I was born, never to be found. When I was young I used to entertain fantasies that he was still alive somewhere in Flanders, perhaps running an estaminet and married to a fat jolly Frenchwoman. The unquestioning acceptance of his death by my grandmother and my father seemed woefully unimaginative to my tactless teenage self, and I like to think that some similar feeling prompted Sebastien Japrisot to write this remarkable novel.