Summer Knight is where I think the Dresden Files really took off, at least for me. It's a story which moves away, slightly, from the private detective genre and more into the realm of "high fantasy in a modern setting." It introduces the character of Queen Mab, one of the series most enduring characters, and raises the stakes to the point Harry's failure will lead to the slow death of the world.
The premise is Harry has been hired by Queen Mab, ruler of the Winter Fae, to find the murderer of Ronald Reuel the titular Summer Knight. Harry doesn't want to do this but is forced into the job by the White Council lest they revoke his title of wizard and hand him over to the Red Court vampires who still want his blood. Complicating matters further is the return of Harry's childhood romance, Elaine, who is working for the Summer fae.
Part of what I like is it's a story built around the Fair Folk. While they're hardly unused in urban fantasy, it's rare they're as well-developed or nuanced. The Unseelie Court are mostly horrible people, inhuman predators without an ounce of humanity, but they aren't precisely evil either. Well, most of them aren't evil. The Summer Court is supposed to be the "good guys" amongst the fae but they have their dark side too. The book has a lot of cleverness about it, too, with Ronald Reul being the middle initials of J.R.R Tolkien.
Summer Knight makes excellent use of characters and plot developments from previous books to round out the cast. This is the book I started liking Murphy in, for the first time. There's an action scene which takes place involving a Walmart that's a blast. Her character is softened a bit from previous volumes and much more likable. While I was still ill-disposed to her due to the events of Fool Moon, she did a lot to regain my respect.
I liked the relationship between Harry and Elaine, but it's a little too compatible to be interesting. They're childhood friends, both wizards, and neither side has any real reason not to become involved. In this, I'm grateful to have Jim Butcher substitute the very real trauma which passed between them. Even if Harry and Elaine are able to reconcile over what happened years ago, the feelings they've carried from that event stick with them. I'm not a big fan of the Murphy and Harry alternative, though, and am fond of other romance candidates.
The supporting cast is great with several characters I wish had shown up more often in the resulting series. Mab is a particularly awesome because Harry is desperate to be the Good GuyTM with a capital G. Mab, however, represent the necessity of the lesser level. She's vicious, cunning, and wicked but a person who has an important part to play in the world. Forcing Harry to work with her is a source of great drama and tension which reoccurs throughout the series.
Summer Knight is funny, exciting, and filled with excellent world-building. It isn't my favorite of the series but it's a novel I've read on multiple occasions. That's about the highest praise I can give a book. A good book will entertain you for a day. A great one will entertain you for a week.
This is averaging about four or five days so far.
Buy at Amazon.com