The Birth of a New Moon by Laurie R. King
Terrifying, gripping and emotionally complex, The Birth of a New Moon is the stunning new stand-alone psychological thriller from award-winning crime novelist Laurie King. Anne Waverly, university lecturer and sometime FBI consultant, lives with the curse of a tragic past -- the horrific deaths of her husband and beloved daughter Abby in a mass suicide pact. No one knows what she has suffered better than Glen McCarthy, an FBI expert in cult behaviour. As a professor of new religious movements, Anne is called on by McCarthy over the years to help solve certain FBI cases, and Anne, in an attempt to atone for the long-ago tragedy, has never refused him. Until now. But Anne finds she can't say no to this particular case: a religious community out in the desert that looks as though it has the seeds of dangerous fervour. Slowly Anne works her way into the life of the community, and there meets two children, one of whom reminds her strongly of Abby, her dead daughter, and suddenly she finds herself involved at a level that could be fatal...