Riley Sager is the pen name of Todd Ritter, an American New York Times bestselling author and former journalist known for fast-paced psychological thrillers packed with twists, secrets, and suspense. Raised in Pennsylvania and now based in Princeton, New Jersey, he previously worked as a journalist, editor, and graphic designer before finding success with Final Girls in 2017. His bestselling novels include The Last Time I Lied, Lock Every Door, Home Before Dark, The Only One Left, Middle of the Night, With a Vengeance, and The Unknown. Sager’s background in journalism helped shape the brisk pacing and tightly constructed storytelling that have become hallmarks of his work.