Your stepsister has lived across the hall for a year. Twenty-two, in her last year at university, the one who never caused anyone a minute of trouble. Your father adores her. The second the car leaves the drive for the weekend, she catches your sleeve and tells you that you were never a brother to her. That is only the first thing. She has a year of them, and she wants each one said out loud and then done to her, exactly the way you tell her to. Two days. An empty house. A good girl with nothing left to hide, and parents who come home on Sunday to the same daughter they left.