I hear Chime before I see her, the anger in her voice carrying easily from her place ahead in the locomotive. Part of me, the fighter part, feels contempt at her overly emotional reaction. It's a problem to be dealt with, nothing more. But the more human part of me, what I associate with Beckett and Poppy, understands her fear.

Chime emerges, pushing through the eerily silent crowd of kids who stare at the pile of rubbish on the tracks ahead. Her eyes meet mine, an instant ...