If this fourth offering in Cooper's series featuring British barrister Trish Maguire (after 2000's Prey to All) maintained its initial oomph, it would be a superb mystery. Alas, it comes up short in the end, as if the author was in the dark about how to wind up the busy plot. Responding to screeching tires and a woman's cry for help, Trish dashes from her London flat to find the driver hysterical and a seriously injured young boy pinned beneath the car. After an emergency team rushes the youngster to a hospital, Trish checks on his condition and discovers not only that she and the lad have an uncanny resemblance but that her name and address were sewn inside his clothes. Terrified, the boy refuses to divulge any information, so Trish does some investigating on her own. Trish's violent and philandering father, Paddy, left Trish and her mother while Trish was still small. Could this be his child? The relationship between Paddy Maguire and his daughter, only reestablished a few years earlier, is still rocky, but Trish must know the truth even if it means destroying still-fragile ties. A stressful court case, a miscarriage and a significant other muddy an otherwise excellent brew. Doing further damage to the story are the absolute tunnel vision of Chief Inspector Lakeshaw, who investigates the brutal murder of the boy's mother, and late and implausible developments involving the thuggish Mikey Handsome and his dear old granny, Lil. (Aug. 26)