A serial killer on death row challenges a forensic linguist to solve his final puzzle in a novel of breathtaking mind games by the Wall Street Journal bestselling author of The Lies You Wrote. Forensic psychologist Callum Kilkenny lost his wife, Shay, to the very serial killer he'd hunted for five years. When Nathaniel Conrad--known as the Alphabet Man, for his love of tattooing codes onto his victims' bodies--was condemned...