“Has everything—a terrifying plot . . . breakneck pace . . . vividly drawn characters.”—John SaulKate Bennet. A bright hospital pathologist with a loving husband and a solid future. Until one day her world turns dark. A strange, puzzling illness has killed two women. Now it endangers Kate's closest friend. Soon it will threaten Kate's marriage. Her sanity. Her life. Kate has uncovered a horrifying secret. Important people will stop at nothing to protect it. It is a terrifying medical discovery. And its roots lie in one of the greatest evils in the history of humankind.