Shadowfall by Tracy Revels
"If you are reading these words in some time and place far from my own . . . then you will no doubt consider me a madman. But I tell you they are true. And yet they must never be known."
I read this book earlier this year. I thought it was an interesting take on Holmes. Without giving away too much of the plot, Revels pulls the reader in with the first page by giving, though it's not labeled as such, something of a prologue where Watson speaks of no one having any idea who the true Sherlock Holmes was. That even with this reveal, most likely no one would believe what may just be seen as the ravings of a madman.
I will say that if one is looking for the standard Holmes and Watson, they won't receive it from this book. The supernatural elements alone prevent that. However, there is the old-fashioned feel and comradere present between them, which I liked.
It's not a long read, but despite some grammatical and spelling errors (don't remember exactly where, but 'aloud' is used instead of 'allowed,') I enjoyed it. Revels has written a sequel that was recently released called Shadowblood. I do look forward to reading that one.