About 15 years ago my mum told me about a book she read and I'm trying to find out what the title is. It wasn't a series but a single book and was most likely in English.
It was about a walled off place full of crazy people (a compound that was a giant dome with a lot of technology and where they were put for testing/experimentation?)
The book follows the story of a boy that's seemingly not crazy and another person who also seems sane. During the story they find out that a sane person is in the compound and that the person can be set free if they travel to a certain place in the compound. I think the protagonist had a walking stick and someone was beaten to death with it during the story. The book makes you think it was someone else but it turns out the protagonist is an unreliable narrator and he did it. At the end he kills (chokes?) the other person he was traveling with who turned out to be the sane person that was spoken about earlier in the story. You also learn that the narrator was always crazy and knew he was from the start. He had lied about being sane and hid his psychopathic and weird traits from the guy he killed. I don't remember why he killed him but it was right before the sane person was about to be set free.
I'd really love to read this story even though I'm already spoiled about the ending. Does anyone know what book I'm talking about?