“I’m wholly disinterested. I just want to know what happened,” says Emma Gnatche, and she just may be right. As part of her research for her thesis in criminology, she happens on the case of Andrew Lutterworth, an accountant who confessed to a fatal hit-and-run accident, then abjured the confession but got convicted anyway. Lutterworth still swears he’s innocent, even though his insistence is probably going to lose him any chances at his upcoming parole hearing. What kind of results can Emma get from giving him a polygraph test? A bizarre surprise, since he seems untroubled by the most probing questions about the incident; it’s only the innocuous control questions that send the needle skittering off the chart. Emma’s friend, romance novelist Willow King (The Drowning Pool, 1997, etc.), has meanwhile dug up evidence, through a few seignorial inquiries, that bears out Lutterworth’s story—evidence the police missed four years ago. If he has nothing to hide but his grief at his son’s shockingly premature death at 14, why is Lutterworth behaving so suspiciously? Despite the lead detectives’ tiresome mutual self-congratulation (“You are wonderful, Willow,” etc.), the marvelously edgy portrait of Lutterworth—by turns cringing, wheedling, apologizing, yet threatening—makes this the best of Cooper’s seven books.