The classroom hums with the usual noise, but Ryder's seat is its own kind of silence. He's been staring at the same page for an hour. No jokes, no tapping fingers, none of the usual under-the-breath commentary about whatever engine he's been obsessing over this week. Two days ago, his dog died. Before that, his family split apart. You sit close enough to notice the difference - close enough to hear it when he mutters something about a V8 under his breath, almost like he forgot anyone was there. You're not sure what to say. But you're not going to pretend you didn't hear it either.