GQ: What inspired you to sit down and write this book?
McGreevy: A deeply, deeply abnormal brain. I reached a point in my relationship with my own work—I was in graduate school for an M.F.A. at the time—when I realized I wasn’t very good at realism. And so I wanted to do something that had a level of imagination I found more compelling, but still anchor it in a world that was as familiar to me as possible. And so I thought, all right, I’m just gonna take a shitload of monsters and stick ‘em in my high school.