“I love you, but I can’t stay longer. It may be a while before I speak to you again. I’m so happy you were my first, Theo, and you were worth all the heartache. I hope I wasn’t living in some alternate universe where I wasn’t actually your first love, too. But this universe is the only one that matters, and I have one last question for you: I didn’t get our history wrong, did I?” I read, glancing up at Dumbledore, sitting there with his eyes closed, nodding his head up and down.

“So that’s it?” he asks as I close the book and push it into my backpack,...