Seanan McGuire is an excellent writer. This series gets better and better, the plotting and storytelling are excellent, the characters are interesting, and there is no relationship angst (personal problem for me).
The major storyline concerns the Queen of the Mists. She banishes Toby from her realm. While trying to figure out how to get unbanished, mayhem ensues. Toby enlists the aid of most of her allies, including the Ludaieg and Tybalt, Quentin and May. There are mysterious coffeeshops and libraries. And oh yeah, Toby loses her addiction to coffee. Go figure!