QUOTE : My father told his acquaintances about that for years, even though both Hannah and I had given up on wormholes and the Child Genius series very soon afterward. That must have made my father sad, as it had made him sad when we stopped being excited about family vacations, when we stopped being open about our interests, and left home and pursued lives of our own. It was just regular growing up, of course, the kind everyone does, but it still made him sad, I know, like the memory I have of the time he dropped me off at the train station when I was going back to Chicago. I could see him through the window of the train, but he couldn't see me through the tinted glass. From up in the train, he looked so small. If he'd seen me, he would have smiled and waved, but he didn't know I could see him, and the sadness on his face was exposed to me then. He looked lost. He stood there on the platform a long time, even after my train started pulling away, still trying to catch a glimpse of me waving back.