Harry Dresden, professional wizard and newly-minted Winter Knight, must kill an immortal in order to prevent a magical jailbreak that would destroy Chicago and large portions of the surrounding area. Harry Dresden has just assumed the mantle of the Winter Knight, and his first assignment isn't easy. Mab, Queen of Air and Darkness, wants him to kill Maeve, the Winter Lady. Trouble is, the Winter Lady is immortal, and she wants Harry dead.
After leaving Arctis Tor and re-entering modern-day Chicago, Dresden seeks out information by stealing Bob the Skull from Waldo Butters's apartment. He learns from Bob that Maeve can be killed on Halloween—tonight.
A series of attacks by Maeve's allies forces Dresden to seek assistance from other allies, and he quickly brings in his former apprentice, Molly, his half-brother, Thomas, and Vaddurung, the CEO of Monoc Securities (also known as Odin), whom he meets at McAnally's pub. Between Molly and Odin, he learns that the island called Demonreach, which has accepted Dresden as its Warden, is going to explode in a few days unless Dresden can find a way to prevent this. After Odin leaves the pub, an Outsider attacks, and is only narrowly driven away, leaving them to wonder what interest the Outsiders have in this matter.
Dresden meets with Lily, the Summer Lady, to request that her enforcer, the Summer Knight, allow Dresden to move about Chicago freely for the next 48 hours. Maeve and Lilly both attend the meeting, and Dresden learns that an Outsider force called Nemesis is interested in destroying all of reality, and is capable of turning otherwise sane and reasonable people into its puppets. Maeve reveals that Mab, Dresden's boss, has been tainted, and must be killed tonight if there is to be any hope of preventing utter chaos.
Dresden feels conflicted; two people, neither of whom (as sidhe) can tell a direct lie, have told him contradictory things. He seeks information from Titania, the Summer Queen, and the Mothers Winter and Summer. Mother Summer takes him to the Outer Gates, where he meets with the Gatekeeper and learns more about the nature of Nemesis and the relation between the Summer and Winter Courts of the sidhe.
Dresden realizes that the island is going to be assaulted from the outside, and sends word to Thomas's sister Lara and to Johnny Marcone that two locations on the shores of Lake Michigan are ideal locations for such a disruptive ritual to take place. The island is another—but as it will only accept Dresden and known allies, Lara and Marcone are not good candidates for checking the island.
The Wild Hunt catches up with Dresden and Karrin Murphy just as plans are finalized to get Thomas, Molly, Mouse and others to Demonreach. Dresden is able to lead the Hunt on a wild goose chase through Chicago, eventually managing to best the Erlking and Kringle and take over leadership of the Hunt. They go to the island, disrupting a series of barges that foes allied with the Outsiders are using as platforms for a gigantic ritual, and then head to the center of the island, where Lily and Maeve are attacking the avatar of Demonreach itself. Dresden faces them, realizing that Mother Winter gave him the clue he needed to know that Maeve (not Mab) was the one who'd been tainted by Nemesis, and summons Mab to help him.
In the fighting, first Lily and then Maeve are killed, with Lily's Mantle going to Sarissa and Maeve's Mantle going to Molly Carpenter. The island is prevented from exploding, and the story ends with Dresden staying on the island to carve a new wizard's staff from wood that had grown on Demonreach.
Best part of story, including ending:
The sidhe were shown to be alien but understandable. Large amounts of the meta-plot are revealed here. I love the character development as Dresden fights against the influence of the Winter Knight's mantle.
Best scene in story:
When Mother Summer takes Dresden to the Outer Gates and he realizes the enormity of the ongoing conflict. He'd always thought of Winter and Summer as being enemies, and they are certainly opposed, but he realizes here that they are united against the darkness beyond. The descriptions are glorious and the importance of what the Winter and Summer Courts (as well as the Gatekeeper) do is jaw-dropping.
Opinion about the main character:
I generally like Harry Dresden's sense of humor, his resourcefulness, and his inability to shut up when he's in trouble.