Amos Walker’s Detroit, always bleak, has now dropped down in class to a virtual wasteland. Or maybe it’s just that Walker himself, in his 13th outing (The Witchfinder, 1998, etc.), returns to us suffering terminal weltschmerz. Oh, he goes through the motions. When Merlin Gilly, who once knew important people, touts a job, Walker does check it out—even a disgruntled, complaining, world-weary p.i. has to eat—but his energy gauge is hovering over empty. At any rate, he meets with Harold Boyette, consultant to the Detroit Institute of Arts, and hears about The Hours of the Virgin. This gorgeous piece of 15th-century illuminated manuscript has been heisted, and Boyette wants it back. He says he’s been contacted by the Virgin-napper, who—ll let it be ransomed for $100,000, which Boyette is more than willing to pay. Walker’s job is to ride shotgun and make sure the exchange takes place smoothly. If all goes well, he gets ten grand. Predictably, all does not go well. Somebody takes a shot at Walker, Boyette disappears, ditto the ransom money. It turns out more is involved for Walker than a botched assignment, and pretty soon he finds himself investigating the 20-year-old murder of his partner, a crime to which the Virgin is (rather tenuously) connected. Eventually, Walker does get around to collecting his villain, but the manhunt drags, sags, and lags while the famous Estleman dialogue generates hardly a crackle. The line between hard-boiled and curmudgeonly is thin, but the p.i. who crosses it leaves his charisma behind. Walker might need another hiatus.