O'Shaughnessy (Invasion of Privacy; Motion to Suppress) brings back Lake Tahoe-area defense attorney Nina Reilly in a legal thriller that founders on coincidence. When Nina takes a romantic hike with handsome DA Collier Halloran, hoping to distract him from the long-unsolved hit-and-run death of his wife and the pressures of an upcoming election, their jaunt is anything but idyllic. A fierce thunderstorm lashes the mountain they're climbing; and they watch, horrified, as Raymond de Beers, the father of a squabbling family that had pushed past them on the trail, tumbles from the summit, apparently done in by a lightning bolt. Collier has a flashback to his wife's murder, and Nina refers him to her ex-lover, PI Paul van Wagoneran, to seek some closure by finding the killer. Then Quentin de Beers, the dead man's wealthy domineering father, insists his son's death was no accident. This sends the widow, Sarah, to Nina for help. After that, things get really complicated: Raymond's body is stolen; Quentin goes missing before the judge can rule on the case; and Sarah is sure her twins, Jason and Molly, are involved. Meanwhile, PI Paul tracks the car that killed Collier's wife and falls for a witness to the hit who's hiding a major secret. Not surprisingly, the two cases--the death of Collier's wife and the death of Raymond--converge, and, of course, Nina and Collier end up opposing each other in court. The action, while complicated, is fast and furious. But all that energy can't cover up unlikable victims, thin motivations and some uncharacteristic histrionics from Nina, all of which render the novel inferior to O'Shaughnessy's previous efforts. (Aug.) FYI: Perri O'Shaughnessy is the pen name of sisters Pam and Mary O'Shaughnessy.