Framed by Watson as a long-hidden manuscript which couldn't be published during the lifetime of anyone involved, this is as dark a mystery as any of the canonical stories. Filled with references to other Holmes adventures (I had great fun playing spot-the-allusion as I read) and capturing the voice and power of the original stories in a way that few other of the pastiches I read have done, The House of Silk is thoroughly enjoyable.
There are some regrettable typos and other errors scattered throughout, but they're no reason not to read this book. I think you'll be glad you did.