I dug up my copy of Knight Errant, which was published several years ago, and enjoyed the re-read, remembered how much. I liked it the first time around. It is only available on Amazon second hand. There is a hardback and paperback edition, I don't think it's on Kindle.
This is a volume of three novellas that record three of Holmes failures, based on other cases in the Canon: Mrs Cecil Forrester's "little domestic complication,"; "Merridew of abominable memory," and "The Smith-Mortimer Succession." Often I think that pastiche writers get the character of Holmes and Co right but not the sense of Victorian melodrama, or they try too hard to "write Victorian" using language that is so high-flung and exaggerated that fidelity to Holmes' character gets lost in the mix. The balance here is just right.
The author has written several Holmes short stories since, appearing in the MX Publishing anthologies. Definitely one of the better pastiche writers around.