It was really disturbing. I actually enjoyed most of the book and was reading from the perspective that we were meant to be sympathetic to the sister, then towards the end it suddenly seemed like we were supposed to see her as manipulative, even though she only ~tricked~ her brother because she was so desperate to get out. The whole family were lying to him anyway and telling him what they wanted him to hear, not just the sister, but I definitely got the vibe that we were in some way meant to root for the family in the end when they all stayed together, even though they were all truly terrible people? (They ended up in the basement because they wanted to protect their oldest son, who was mentally handicapped, after he raped and killed a young girl. The sister was forced into the basement with them after she tried to call the police, but then she was already being treated as the family pariah after they blamed her for the accident which left her brother brain damaged)

It was a book that I really enjoyed when it was told through the innocent perspective of the little boy who had been born in the basement, but it really became quite disturbing in the final section when the author seemed to want to present it as ambiguous as to how far you should go to protect your family. It made a lot more sense when I was assuming that we were meant to be repulsed by how twisted and dysfunctional they were, but instead it seemed like he intended for his ~twist~ to throw a new light on everything, and for the reader to then question what choices we might have made in their place