Canadian author Bowen's enjoyable if flawed 12th Joanne Kilbourn mystery (after 2008's The Brutal Heart) focuses largely on the rich family life of the Regina, Saskatchewan, academic, who gets involved in a convoluted custody case and murder. At a pre-Christmas concert, a troubled young woman hands a baby boy to teenage Isobel Wainberg with a message for Isobel's mother, Delia, who's a friend and law partner of Joanne's husband, Zach Shreve. The young woman turns out to be Abby Michaels, who says she's Delia's daughter. When Abby is discovered raped and strangled in a car in a snowy parking lot soon after her stunning revelation, her death adds to the confusion and consternation over the fate of her six-month-old son, Jacob. Questions of parentage and custody cloud the murder investigation, while Zack's health (he's a paraplegic) presents still more difficulties. Bowen's resolution may well disappoint, but her realistic depictions of Joanne's extended caring family should please fans. (Aug.) (c) Copyright PWxyz, LLC. All rights reserved