High Above the Trenches : A VERY LONG ENGAGEMENT, <i> By Sebastien Japrisot (Farrar, Straus & Giroux: $23; 327 pp.)</i>

Procrastination is the heart of writing, and by that measure, this review starts off with a lot of heart. You can struggle for days, not to say what you want but to resist saying what you don’t want. It has been a battle to avoid writing of Sebastien Japrisot’s novel about World War I as a kind of latter-day “War and Peace.” I lost. It is a kind of “War and Peace.”

This is not to call it an epic--though in 300 compressed pages it has something of the spaciousness--or to fit it with the Great Novel collar. I think it could wear one, but a daily reviewer should probably leave the collar to time, and meanwhile regard the neck. The Tolstoy reference is specific. “A Very Long Engagement” finds a chilling and humane way to evoke the trench-fought war of 1914-18, whose self-corrupting stasis was only an extreme variation of what lodges in many other wars. And while telling of France’s war, it wanders around telling beautifully of France’s peace.

Mathilde, a chestnut-haired, green-eyed young woman whose independent mind is in no way curbed, quite the contrary, by the fact that she is crippled, and is fortified by her position as the indulged daughter of a wealthy family, learns in 1917 that her lover has been killed in action. He was a fisherman’s son in the Landes, where Mathilde’s family goes every summer. After some resistance he had been acknowledged as virtually her fiance.

It would have been ordinary fading grief; or perhaps not, since, as we come thrillingly to see, there is nothing in the least ordinary about Mathilde. But in 1919, a letter comes from a sergeant in a nearby veterans’ hospital; he is dying and wants to see her. What he has to tell launches a book that is many things: a war story, a story of official corruption, an idyll of young summer love, and a rich and most original panorama of French men and women living in peace and robbed of it. Finally, giving it all an intent energy, it is a hybrid of the detective story and the classical quest.

To explain the quest and the intuitive and stubborn detecting that propel Mathilde and her wheelchair into literary splendor, there is the scrap of history out of which Japrisot has fashioned his novel. In 1915, after a year of mud and massacre in stinking trenches, French soldiers were shooting themselves in the hands or feet to get invalided out. General Henri Petain, the hero of Verdun and, in 1940, of the Vichyites, wanted to shoot 25 of them. Changing his mind, he ordered something less absolute, perhaps, but more ghastly. The order was kept secret and only confirmed, 50 years later, with the publication of a fellow-general’s memoirs:

“He orders them bound and tossed over the top of the trenches closest to the enemy. This is to be done under cover of night. He didn’t say if they’ll be left to starve to death. Character, energy! Where does character end and ferocious savagery begin. . . .”

Manech, whom Mathilde thinks of as “her little fisherman”--the other soldiers called him Cornflower--was one of five prisoners whom the sergeant had escorted, bound, to the front; and then through the trenches to a rampart named Bingo Crepuscule, where they were forced over the wire at night into no-man’s-land. There were German flares, a little machine-gun fire. Several of the five were heard digging; some hours later, the Bingo company attacked the German lines and most were killed including the captain. Presumably the five prisoners perished, though a company survivor whom the sergeant later saw was not absolutely sure.

Mathilde listens to his account in silent shock. All she can think of is to tell the ill, slovenly sergeant to button “his repulsive fly.” Later she weeps; and her mission begins to grow in her. She travels, with the stalwart help of the family chauffeur, to various parts of France. She hunts down widows, lovers and relatives of the other four prisoners. She writes their friends, landlords and parish priests.

She enlists the family lawyer in Paris, with his mysterious Army connections and, as it turns out, his mysterious evasions and vague threats. She advertises in newspapers and receives dozens of answers, one or two useful. She employs a rickety but unstoppable private detective who has fallen hopelessly in love, not with her, but with the splashy flower paintings that her father’s influence enables her to show in a Paris gallery. She makes her way through lies, half-lies, misapprehensions. She tires, comes to stalemates, starts over again. Finally she will find out what happened to her little fisherman and the four others.

It doesn’t come with the force of revelation but with quite another force; that of life, of history and of Japrisot’s art. It is impossible to describe all the different things the author succeeds in doing without making this into a list; still less is it possible to convey how he does it. His close-ups and panoramic views are not only equally intense and compelling, but they merge. There is hardly a detail that does not tell far more than itself.

Each of the five prisoners--Eskimo, the bluff and life-loving carpenter who is the hero of his Paris bar-set; Ange, the pimp from the Marseilles milieu; Six-Sous, the eloquent working-class Socialist; That Man (for lack of a nickname), the silent and redoubtable peasant; and Manech himself, youthful and frail--are five chapters of France. Other chapters are embodied by Ange’s prostitute lover, whose search, parallel to Mathilde’s and fatally successful, is for revenge rather than knowledge; by Mathilde’s father, a bourgeois out of the Enlightenment not Balzac, and by the captain who has to execute the dreadful order. He is a schoolteacher and stamp-collector--the detail will provide an early clue in Mathilde’s search--and he does more than curse his assignment. His fatal charge of the German lines is a suicidal attempt at rescue.

Japrisot, lucidly translated by Linda Coverdale, gives us not only the story but its characters in a series of successive passes, each of which uncovers a new layer of color and configuration. If the five prisoners are a colorful assortment of French types, they deepen into individuals whose declarative vividness gives way to something more complex and mysterious. As for Mathilde, her evolution and revelation is both similar and different.

She begins with immense charm, but with elements of snobbery, willfulness and sentimentality. She becomes a genuine heroine--not of courage and persistence, merely, but of sheer brainy energy--yet the other qualities remain. We do not so much change as grow, Japrisot suggests, and nothing is lost. There is a brilliant light on her from beginning to end, and her only mystery is that of a life lived so completely as to entirely fulfill itself.