Halfway through the day, a city appears, rushes toward us. Kansas City is big, sprawling. Tempting. But we've come a long way, still have lots of coal to keep us going. And more than enough food.

"Not worth it." Chime glares at the approaching buildings form her place at the rail as though they've offended her. I see her shudder a little, lean into Brick who rolls his eyes behind her back, making fun of her weakness. When he catches my gaze, he winks.

It turns out she's ...