Well, magic works in mysterious ways. This movie about 4 prisoners, trying to escape with the help of spells, written by another prisoner centuries ago was a superb occult thriller with a surprising end and lots of suspense. Even if it had something of a theater-play (almost everything happens in the cell) it never got boring and it was acted very well. In the tradition of "Cube" you felt trapped with the Characters and even if they were criminal, you developed some sympathy with some of them, only to change your mind by the twists the story takes. Some happenings catched you off guard and there was always a touch of insanity in the air. Altogether intense and entertaining and as I didn't expect anything (a friend rented it), it was a positive surprise!