Incarceron

Incarceron is a prison so vast that it contains not only cells, but also metal forests, dilapidated cities, and vast wilderness. Finn, a 17-year-old prisoner, has no memory of his childhood and is sure that he came from Outside Incarceron. And then Finn finds a crystal key that allows him to communicate with a girl who claims to live on the Outside.

Catherine Fisher is an acclaimed novelist and poet, and has written many fantasy books for young people. She lives in Wales.