I wanted to write a book about a prison. An extraordinary, vast, talking, dreaming living edifice, which contains villages and forests as well as cells and corridors. Whose Prisoners can never escape, so that’s all they can think about, and they tell stories of a legendary man called Sapphique, who once escaped, to keep themselves hoping. Incarceron is a dark and violent place, an experiment which has gone wrong. When Finn wakes up in there with no memory he’s sure he doesn’t fit, that he came from outside. But no one does, as his oathbrother Keiro tells him scornfully.

Outside in the beautiful, golden 18th century world of the Realm, where time is forbidden, Claudia is the daughter of the Warden of Incarceron, though her father never goes there and she has no idea where the prison is. But she has to marry Prince Caspar, and she hates him, so she breaks into her father’s study. There she finds the crystal key..

Incarceron and its sequel are certainly the most complex books I’ve written. They were a wild roller-coaster ride of fun, invention, despair and worry. Sometimes I thought I would never get through it; other times the book seemed to write itself, the characters took over, things happened I hadn’t even foreseen. I had a really mixed bunch of characters, the austere, dangerous Warden; feisty Claudia, arrogant, vain Keiro; Finn who never quite tells the truth. And Jared, Claudia’s gentle, clever tutor. There are lots of relationships of various sorts going on here which I tried to imply more than state. Also there are a few mid-blowing twists in the story that seriously jolt the reader into amazement. At least I hope they do!