A Holmes pastiche where Watson is the main character and gets the girl. Set in a Britain ruled by Druids, isolated from the rest of the world and technology (cold iron, bad for druids) by magic defenses. The contraption on the cover made me think it would be more "steam punk," but that's just Wells' time machine.
It took me a little while to get into the story. The author starts with a chapter that never seems to get fully explained, and then builds the rest of the novel as if it were a children's serial, one exciting Victorian hijink after another. In the nature of Victorian pastiche, the author seems to want to jam in way too many characters. A Night in Lonesome October or the first volume of League of Extraordinary Gentlemen do this more smoothly. Watson is very wishy-washy, Holmes is a huge Mary Sue. Both can be a bit wearing. The "twist" of Watson's identity is telegraphed and never truly surprising. I put it down and picked it back up several times before I finished it. It's an okay read if you are a Friesner completist, a huge face of Victorian pastiche, or only have Clive Cussler books to read otherwise.
Frankly, that first chapter, which seems to hint that the Holmes character actually took his identity from Watson's stories about him, is the bit I would have liked to see developed the most. I particularly liked her hint of this alternate America. "Dons from the great western outposts, Mynheers from the eastern trading centers, voyageurs from the south, redmen of the Seven Nations, and a sprinkling of joy seeking Turks and Venetians from Florida thrown in... No matter their many different races and governments, the Americans all took their theater seriously."