If you are looking for a thorough history of the Church of Scientology, then this book is not for you. I'd recommend Piece of Blue Sky or Inside Scientology instead. But if you saw either of John Sweeney's Panorama documentaries and came away wondering what happened between scenes, like I did, then this is most definitely the book for you.
John Sweeney's "exposes" of Scientology turned into more a study into just what the Church does to those who try to expose it. And here, with the benefit of hindsight and evidence from the Church's side of the story, John Sweeney paints a vivid picture of a Church that is dying from within but still strong enough to lash out at those it feels oppose it.
It was fascinating reading the (allegedly real) leaked documents showing the communications between the infamous Tommy Davis and Scientology HQ. The level of abuse in those communications is not surprising to someone who has been studying the workings of the Church for a while, but the documents still leave one
feeling very uncomfortable.
It's an easy read, and makes a good way to introduce yourself to some of the basic history of Dianetics and Scientology. That history is nothing if not utterly fascinating and, occasionally, deeply disturbing.
And to get a picture of the inner workings of the Sea Org, Scientology's holy order, and to get corroboration for what may seem some outlandish claims made by Sweeney, check out Blown For Good.