Solid urban fantasy; I'd almost decided not to read it based on reviews , but am glad that I did. The humor is very good, the story good also, and the writing is very good. The story involves not just the last Druid, but a cast of characters that are quite intriguing and unexpected in their characterizations. I don't know much about Celtic lore, but as entertainment, it was both well explained and logical within its rules, which always makes for a better read. It was a good start to a new series, and I'll be visiting this world again, I'm sure.