Dr. Theo Cray is on the hunt for a killer nurse, and redemption, in a mind-bending psychological thriller by the Wall Street Journal bestselling author of The Naturalist. Dr. Theo Cray has a legendary mathematical knack for catching serial killers. Until his exposure to a mind-altering pathogen knocks him off his game. It has upended an investigation, destroyed his reputation, and left him to question his own sanity...