I expected to like this a lot better than I did. The Chicago World's Fair is an interesting topic, as is a real-life serial killer. However, Larson's writing style really didn't work for me. The author is clearly a meticulous researcher, as evidenced by the extensive endnotes and bibliography, but the sheer amount of minor detail was mind-numbing, and I found the little colorful details about sunsets and so on a bit hard to take alongside the documented bits. The last quarter of the book, which is told as a procedural, moves a lot more quickly than the rest of the book, and I enjoyed the chase. If it hadn't been a book club selection, I would have put it down after 100 pages.