There is a door at the end of a silent corridor. And it’s haunting Harry Potter’s dreams. Why else would he be waking in the middle of the night, screaming in terror? Harry has a lot on his mind for this, his fifth year at Hogwarts: a Defense Against the Dark Arts teacher with a personality like poisoned honey; a big surprise on the Gryffindor Quidditch team; and the looming terror of the Ordinary Wizarding Level exams. But all these things pale...