Small Favor - Book 10 of the Dresden Files series by Jim Butcher. Harry Dresden has had one quiet -- make that dull -- year. For 12 whole months, nobody has tried to kill him. Just as he's settling into these doldrums, Mab, the monarch of the Winter Court of the Sidhe, calls him in for a small favor. (Favors, it seems, are the main currency of Dresden's universe.) What begins as a tip of the hat quickly escalates into deadly matters that pit Harry against two deadly foes.