Not what it says on the tin. The man who loved books too much barely seems to like them at all. The detective is actually a rare book dealer, who sort of accidentally fell into a security side job. There definitely is a world of literary obsession, but you'll only hear tidbits about it between the author's tangents. All in all it seems like a story that would have been adequately covered by an article. The only thing that makes it book length is the author's endless chronicling of her investigations. Protip: the nice thing about you, the author, doing all the research and legwork is that we, the readers, then don't have to. It kinda defeats the point if you write more about your journalistic efforts than about their results.

John Gilkey, the thief, only wanted rare books because they represented the high life to him. It could have just as easily been about fine art, or Faberge eggs. The books he coveted most in fact came from a list of the 100 best books, not his own preference. He didn't even read many of them. Gilkey's actual thefts aren't even terribly impressive, just impressively terrible. No daring break ins, or clever ploys...just lists of credit card numbers he acquired working retail, and a payphone. Ken Sanders, the "detective," is not so much an impassioned super-sleuth as he is a proprietor who (shockingly enough) doesn't like being stolen from.

There is easily enough material out there to write a book about bibliomania; as the author mentions, there are already books on it. I get that she wanted to write more specifically about book theft, but why this thief? I'd wager there's also enough material on book theft in general to write that book, but in it Gilkey would probably be a footnote.