Although it’s architect Adam Dean’s adultery that sets Whitaker’s debut in motion, this is a story in which predictable female figures predominate: best friends; professional vixens; innocent wives; co-conspirators in the battle of the sexes. When sophisticated, calculating Valerie Hughes, originally a colleague of Adam’s and now his mistress, forces him to choose between Sophie, his wholesome wife and the mother of his two adorable young children, and her, Adam, whose feelings are obscure, picks Valerie. But Sophie, although devastated, seizes the initiative and moves out of the family home in Boston’s suburbs herself, leaving Adam to cope with the kids. That’s the one original twist in Whitaker’s tale of marital discord, which is populated with characters tending either toward the unappealing or unconvincing and many of whom come with sharp edges. The exception is saintly Sophie, who emerges sadder, wiser and readier to accommodate an updated lifestyle and a husband who has suddenly discovered human and paternal feelings.Whitaker has moments of insight, but her journey from brittle to peaceable lacks consistency or charm until its closing chapters.