My ten-year-old daughter Sophie developed a routine so precise it almost felt scripted. Every weekday afternoon, the front door would open, her backpack would slide off her shoulders and land by the shoe rack, and without stopping for a snack, a story, or even a complaint about homework, she would head straight for the bathroom. The door would close, the lock would click, and within minutes I’d hear the bathwater running. At first, I told myself it was nothing. Kids change.

Maybe recess had gotten messier. Maybe she hated the sticky feeling of dried sweat after gym class. I tried to be a reasonable parent instead of an anxious one. Still, there was something about how fast she moved, how urgent it felt, like she was racing something invisible. Sometimes she wouldn’t even look at me when she passed. When I finally asked her about it one evening, keeping my tone light so I wouldn’t scare her, she smiled up at me with a smile that didn’t reach her eyes and said, “I just like to be clean.” The words sounded rehearsed, too smooth for a child who usually answered questions with shrugs or rambling stories.