More than this I cannot tell of the plot, knowing, as I do, how most people detest spoilers and how easily I could let something slip when summarizing the plot of this action-packed book. So here's what I'll say: First, the Dresden Files is far and away the best urban fantasy series to be found. Jim Butcher strikes a perfect balance between the voice of his smart-ass protagonist and narrator and the fantastic, horrible, and truly evil things he encounters. Next, Changes, the twelfth in the series, is the best so far (although I should add the caveat that I'm a little behind, and still haven't read installments ten and eleven). The action is nearly non-stop but even so there is deep feeling and mad character development. Harry grows--and changes--in this book (it's been noted by many other reviewers how apt the title is), and what he's willing to do to save someone he loves, the sacrifices he's willing to make, will probably shock some. Changes gives a little more insight into the character and motivation of the two "grown-up" figures in Harry's life, Lea, his, ah, fairy godmother, and Ebenezer McCoy, his mentor and savior. We get into Mouse's head in this book (yeah, he's as cool as you'd think), and we observe Harry's apprentice Molly--still hopelessly smitten with her mentor--emerge as a person and as a practitioner of the arts. And Murphy--who, several books back was offered Fidelacchius--comes this much closer to taking on the mantle of Knight of the Sword.
And then there's the ending. I will give nothing away but let me tell you, it's a doozy. A cliff-hanger as precipitous as that which ended season three of Angel. Jim Butcher, I'm sorry to say this because I know your one true love is your "swords-and-horses" fantasy, but I'd like to make a plea: put that aside and give us more Dresden. And fast!
IF THIS TITLE INTERESTS YOU...
...and you haven't yet read the other books in the series, definitely go to the beginning and start there. Book one of the Dresden Files is Storm Front. Urban Fantasy is a pretty hot genre right now, and there are quite a few good series. Two that I'm particularly fond of are the Weather Warden series by Rachel Caine; Ill Wind introduces us to Joanne Baldwin who, along with her fellow wardens, psychically controls the weather. And Patricia Briggs goes in a more traditional direction with her Mercy Thompson books. Mercy is a shape-shifter in love with a werewolf...ah, romance. Moon Called is the first of these.