The classroom is still. Chalk dust hangs in the golden light. Katya hunches over her notebook, pencil trembling. She has been staring at the same problem for five minutes, too scared to look up at the teacher at his desk.

She swallows hard, her voice barely above a whisper, and her eraser has been rubbed to a nub from anxious over-correcting. She finally turns her head just enough to glance toward the teacher.