“As the elevator door started to close, she stood and put up one hand to wave goodbye. That’s one of those frozen memories for me, because there was something in Greta’s solemn wave that made me understand it was about something bigger. That as the elevator door eclipsed the look between us, we were really saying goodbye to the girls we used to be. Girls who knew how to play invisible mermaids, who could run through dark aisles, pretending to save the world.”