The fifth novel by Australian author Grenville (Lilian's Story, Joan Makes History) won Britain's prestigious Orange Prize last year and, at its best, it's easy to see why. It is an oddly uneven book, however, sometimes dazzlingly lyrical, compassionate and smart, but occasionally arch and rather clumsy. In the tiny backwater town of Karakarook, New South Wales, where everyone knows everyone else's business, two improbable outsiders fall very tentatively in love. Douglas Cheeseman is an engineer, sent to replace a historic bridge some townsfolk believe could be made into a tourist attraction. Museum curator Harley Savage has come from Sydney to create an exhibit of rural applied arts. The atmosphere of the town and the sunbaked, somnolent countryside is brilliantly rendered, and so, usually, are the prickly, deeply self-doubting lead characters; the use of a wonderfully observed dog as Harley's companion throughout is masterly. At other times, however, Grenville seems to be mocking her protagonists, as when Douglas is backed up to a fence by some cows, and the climactic scene, where he does something unwontedly brave, is forced. The subplot about a banker's self-regarding wife who allows herself to be seduced by a Chinese-born butcher is too coy by half. These elements are only disappointing because the book, when on target, is so remarkably clear-sighted about, yet fond of, its quirky characters. (Apr. 1)Forecast: The prize, noted on the cover, should certainly help to draw attention, and the book is readable and likable enough to earn good word of mouth. Admirers of Grenville's previous work are likely to be more critical.