Book + Trailer: Sapphique, by Catherine Fisher

ON SALE 12/28/10.
In this stunning sequel to the critically acclaimed INCARCERON, seventeen-year-old Finn has escaped from the sentient prison only to find that things Outside are not at all what he expected. Claudia, the daughter of the prison's warden, has declared Finn the lost heir to the throne. But another claimant emerges, and soon, both Finn's and Claudia's very lives hang on Finn convincing the Court of something that even he doesn't fully believe.

Still trapped within Incarceron, Finn's friends Keiro and Attia hunt for the magical glove, which legend says Sapphique used to escape. In order to find it, they must battle the prison itself. Incarceron has built itself a body and it wants to go outside--just like Sapphique, the only prisoner Incarceron ever loved.
(From the YouTube description)