Dresden learns that Bob used to belong to Kemmler, the most powerful necromancer in a thousand years, and narrowly survives an encounter with an evil personality hidden within the spirit.

Investigating further, he rescues the medical examiner Waldo Butters from Grevane, a powerful necromancer, at the local morgue.

With Halloween fast approaching, Dresden learns that three different groups of necromancers are planning to try and use the two books in a ritual that will turn them into a minor god.

Seeking to stop the ritual, Harry contacts the White Council and prepares to summon the Erlking himself, to prevent any of the necromancers from doing so.

He gives it to Mavra along with a warning: threaten his friends again and he will pull out all the stops, seizing whatever power he can (including the power in the book, Lasciel's coin, and an offer from the Queen of the Winter Court) and make a mission of putting Mavra down for good.