A twisty psychological thriller from Natasha Preston, author of the #1 New York Times bestseller author of THE CELLAR!It's a fight for survival in a building designed to ensure that no one makes it out alive.In Piper's hometown, teenagers keep disappearing, and everyone assumes they're just a bunch of runaways. But when yet another person vanishes, Piper and her best friend Hazel suspect something more sinister is going on.So they decide to investigate, determined to learn th