A detailed look into the history of Scientology. Honestly scary how much they can get away with without the US government being able to do anything. E.g. all the stalking they do to try and get people who leave to come back, or how they abuse their followers (technically willingly, but cmon they're basically brainwashed).
I've given it a 4.5 since it was very detailed and well researched, however it isn't quite as gripping to read as something like a book on Jonestown for example (which is morbid to say).