The Complex started a little slowly, but it was so the reader understood all of Duignan's background, so you can understand why he got caught up in the cult of Scientology. After that, the buildup is phenomenal and fascinating.
Duignan's spot in Scientology was right near the top, after starting at the bottom in the mid-'80s, at the age of 20. He was vulnerable due to his childhood, and was sucked right into the cult's brainwashing.
The pace of this book couldn't have been much better. Near the end, after 22 years in the cult, Duignan reminded me of Red from The Shawshank Redemption, getting free, but reentering a world he doesn't know anymore, and not having any skills from which to draw. (I don't consider that a spoiler because it's like The Titanic - you know the end.)
Scientology has threatened legal action against any bookseller for selling this, so it's very hard to come by. Amazon, Borders, B&N, etc, won't sell it. I managed to get lucky and found it at a small bookstore.