Currently running on Kickstarter, Dark Arts, Dark Acts is Orlando Pearson's first novel length Sherlock Holmes story. Subtitled The Redacted Sherlock Holmes Novels hints there are more to come.
Orlando has produced six short story collections (so far, Volume seven is coming next year) and a host of play adaptations. In the interview he tells us much more about the book set in 1940 in Berlin.
(apologies for the audio near the end - internet challenges...)