Faithless (2005)

In Karin Slaughter's smart but somewhat ponderous fifth mystery Faithless, featuring Georgia medical examiner Sara Linton, the doctor is walking through the woods squabbling with her ex-husband, police chief Jeffrey Tolliver, when the couple discovers a pipe sticking out of the earth. The pipe leads to a homemade wooden box containing the moldy corpse of pregnant teen Abigail Bennett. Abigail, who was buried alive, grew up in a repressive Christian sect, the Church of the Greater Good, and the subsequent investigation lets Slaughter delve into this creepy, sexist subculture. But she overburdens the snappy whodunit with some byzantine subplots involving Sara's tortured relationship with Jeffrey, abortion politics, and the plight of battered women — too much baggage for an otherwise muscular thriller.