Incarceron by Catherine Fisher

This highly touted British fantasy novel is an inventive and engrossing adventure. Set in a future world where "Protocol" is in effect (nothing can be automated, no machines allowed), the tale centers on two characters who live in drastically different environments. Claudia is betrothed to the prince of the land, Caspar, yet she is feisty, rebellious and intelligent and has no interest in marrying the doltish prince. Her tutor, Jared, is a Sapient, a group of intelligent inventors. Jared has taught her about science and machines and she is closer to him than she is to her father, the Warden, whom she is always trying to subvert. When she breaks into her father's office and discovers a crystal key, she makes contact with Finn, a young man who lives in Incarceron, the prison her father oversees. Finn has lived in Incarceron since he can remember and is on the run from his former gang with another Sapient, Gildas, his oathbrother, Keiro, and Attia, a former slave. Finn has also discovered a crystal key and through this can communicate with Claudia. The bulk of the novel details the efforts of Finn and his friends to escape from Incarceron and of Claudia's desperate attempts to evade her impending marriage and help Finn. A true page-turner, the reader is compelled to learn if Finn and Claudia escape from their respective imprisonments. Despite a few episodes of sloppy writing and confusing plotting, this novel is a gem. The sequel is only available in the UK at the moment and I can't wait for it's US release.