What would you do if you were stuck, alone, in the place you hated most in the world? Well, write a past diary, of course. Only this isn’t a diary. Because diaries are books in which teenage girls write how much they love Sirius Black.(His words not mine.) So he’s writing a journal? Oh, Journals are just diaries written by more sophisticated girls in love with Sirius Black. So he’s writing a book. And this might be your only chance to read it.