Book excerpt: Their bloodline is a dangerous mystery. Their secret is a shocking truth. There's something strange about the small, mountain town of Artisan, Arkansas. When hematologist Dr. Carl Martin is called into a Little Rock emergency room, not even his expertise can save Benjamin Rasco from bleeding to death. But why did the man die? His condition shouldn't have been fatal. And no one should have such bizarre red blood cells. Hoping to uncover a reason for the medical mystery, Carl travels to Rasco's hometown, an isolated, religious community nestled deep in the Arkansas Mountains. Instead of answers, however, Carl's faced with more questions--and a mysterious woman who stows away in his car. Sheltered Beth Corbin only wants to see the world for a few days before returning to Artisan, where the town leaders discourage mixing with the outside world. But after talking with Carl, Beth becomes increasingly distrustful of those leaders, and the suspicions she's been harboring about the town become too intense to ignore. Together, Carl and Beth uncover an astounding medical conspiracy that not only affects all the residents of Artisan, but shatters every belief Carl ever held about himself.