The national bestselling author of #HorrorBookTok sensation The Troop returns with a heart-pounding novel of terror about a young woman searching for her missing friend and uncovering a shocking truth. On a sunny morning in June, Margaret Carpenter wakes up to find a new iPhone on her doorstep. She switches it on to find a text from her best friend, Charity Atwater. The problem is, Charity’s been missing for over a month. Most people in town—even the police—think she’s dead. Margaret and Charity have been lifelong friends. They share everything, know the most intimate details about one another…but Charity carries a secret that even she is unaware of. A secret engraved into her DNA helix. For Charity is also known Subject Six, the crown jewel of Project Athena—a clandestine and unorthodox gene manipulation experiment, the brainchild of tech titan Rudyard Crate. And when Charity’s gene sequencing actualizes during a traumatic event at a high school party, it sets in motion a chain of events that will end in tragedy, bloodshed, and death. And now Charity wants Margaret to know her story—the real story. In a narrative that takes place over one feverish day, Margaret follows a series of increasingly dreadful breadcrumbs as she forges deeper into the mystery of her best friend—a person she never truly knew at all…