At this point, the deliciously gloomy, ongoing adventures of the permanently hangdog Jackson Brodie form a kind of seedy, hardboiled modern epic. Depressed but indomitable, a fallen policeman in a fallen world, Brodie here tugs on a slender thread, the search for the real identity of an adopted woman in New Zealand, and an old and desperately unhappy mystery comes tumbling out. His voice duets with that of Tracy, an unmarried police detective of a certain age who seems doomed to a lonely decline until she impulsively and illegally adopts a child. It all coalesces, as things in Kate Atkinson's intricately constructed stories usually do. It's a damned depressing world, but her characters make excellent company there.