I liked this one almost as much as the first one, but I cant really get into the details without giving away spoilers of the first story.
So, yes, it does turn up the extreme and, yes, there is a small twist at the end, but it didn't have the impact of the first one.
Read them in order.
Just as an afterthought he uses the reference of the prisoner thinking he is Charles Bronson. For those outside the UK, you are probably thinking about the movie actor of the DEATH WISH franchise.
You are wrong. The reference is to a prisoner who has been dubbed the most violent prisoner in Britain. There's some interesting reading about him out there, for those true crime addicts.
I really liked these two stories and will be looking for more by this author.