This is amazing on so many levels. First of all, Holmes and Watson are awesome characters with great chemistry and their dialog is very memorable and occasionally really funny. The case and the way Sherlock deduces are fascinating. Also, the writing style worked perfectly for me. The backstory of the crime is really engaging and tragic which makes this feel deeper than just an average detective novel. If I had to name a flaw of this book, it's that the two stories told feel a bit detached from each other and not really like they're from the same book, but they are exceptional stories individually and show the variety in Doyle's writing.