*sigh* I read this book as quickly as I could because it was my first "First Reads" book, and I wanted to write a review so I could increase my chances of winning MORE books. But then I've been dilly-dallying over the review, because, honestly, what am I going to say? "If you enjoyed Sphere and Congo, you've already experienced the more enjoyable parts of Perfect Circle"?? Cortes declares himself an expert on mining, geology, international politics, the CIA, business, and indigenous societies for the purpose of this novel. Everything he says about pygmies in the whole book is laughable if not offensive. The conclusion to the central mystery is fine, I guess, but it's WAY too complicated to make a good conclusion. Yes, the premise is ok, but why do you end up with chapers and chapters explaining exactly how this conclusion could be plausible? And I cannot suspend my disbelief about the character introduced in the last chapters to do all of the endless explaining. If he's here, why didn't he just TELL everyone what was going on? And if he didn't know what was going on, why does he know everything else to explain the historical background behind what was going on? Bah. There are far better Sci-fi books out there. Go with those.