This is totally driving me crazy. A year or two ago I read a REALLY good book. I would put it in the suspense/psychological thriller genre, I guess. It was about a girl who was rescued from a pit in which she and several friends were being held - perhaps over school holidays? Or at an abandoned school? They were early twenties or late teens. Can't remember details, but it's all from her point of view after she was rescued, and there's a HUGE twist at the end. Anyway, has anyone read it? I'd like to read it again or maybe buy it, and I just can't remember the name!