Sapphique

Blurb

Sapphique is a young-adult fantasy and science fiction novel written by Catherine Fisher, first published in 2008 in the UK. It is the sequel to Incarceron, and concludes the story of Finn's quest for freedom. Sapphique was released in the US in December, 2010.
Sapphique is also the name of the legendary prisoner who journeyed to escape.