In his first novel, true crime writer Olsen (The Deep Dark ) brings complex mystery and crackling authenticity to bear on a cold case police procedural. Hannah Griffin has spent most of her life trying to forget the notorious Christmas Eve house fire that claimed her family and turned up almost two dozen other bodies buried in their yard; though the case remained unsolved, Hannah's mother became, posthumously, the de facto prime suspect. Twenty years later, Hannah's a happily married mother of one, a crime scene investigator for Santa Louisa, Calif., and a lifetime away from her traumatic Oregon childhoodâ€"until a series of mysterious events indicates that her mother may still be alive. Hannah reopens the case, as well as old wounds, after enlisting the help of FBI Special Agent Jeff Bauer, the still-haunted chief officer from the original investigation. Thanks to Olsen's true-crime work, the case's particularsâ€"both grisly and mundaneâ€"all carry genuine weight, though his characters can be cloying: Hannah's neuroses occasionally seem more dingbat than damaged, and Agent Bauer's tough-but-tender act is a familiar one. That said, Olsen's flashback narrative shines with lurid, carefully distributed details, and if it ultimately overshadows the present-day plot, his bizarre, many-layered mystery will keep fans of crime fiction hooked. (Mar.)