A girl called Aisha was at a big, busy place with her family — a shopping centre, maybe, or a fair. One minute they were right there; the next, she turned around and they were gone. Just a sea of strangers and noise. Her heart started thudding. The instinct screaming at her was to move — to rush off and search, to push through the crowd looking for a familiar face. Everything in her wanted to run somewhere, anywhere, fast. But somewhere in her memory was a thing a grown-up had once told her about what to do if this ever happened. The trouble is, panic makes it hard to think, and right now the loud, scared part of her brain is much easier to hear than the calm, sensible part.