I would like to give this book 3.5 stars. For me this series gets better as it goes as I've enjoyed each successive book more than the last. This one had a slightly darker quality primarily due to the plots focus on the plight of U.S. chinese community in the late 19th century which was pretty grim. It gave the book a little more heft while still delivering the chracteristic smart aleck humor. The mystery was well constructed and plausible with some surprising (for me)twists and turns.
My one complaint was not with the book but this audio recording of it. THe reader while animated and obviously a professional voice actor, for some reason decided that his role model for Otto (the narrator)was Goofy from Mickey Mouse. I mean he literally had Otto laughing with a charicaturesque "yuk yuk yuk". It was pretty awful and did not at all match my previous impressions of Otto which were a little goofy yes, but also as a witty smartass, who doesn't take life nearly as seriously as his melancholy brother. Anyway, the performer annoyed and I will definitely be reading the next one in the series.