Harry Dresden returns in another Urban Fantasy Mystery. This time, ghosts are running amok, causing chaos and killing people and similar shenanigans. Harry must go out with his new side-kick, Michael a Knight of the Cross, and stop this sudden tidal wave of deadly ghost activity.
Following the exhausting and dangerous trail finds that someone is tormenting and manipulating these ghosts raising them and encouraging them to spread their havoc – and further, in doing so they are thinning the barrier between the real world and the Nevernever, allowing more and darker spirits to emerge. As if that weren't enough, there is something else out there, a Nightmare that is darker than any ghost they've faced that is hunting Harry and his friends specifically.
Harry must find how they are all connected and what lies behind the ghosts, the Nightmare, the thinning of the Nevernever all the while dodging his faerie godmother who hunts him and seeks to drag him away to be her slave – and even that must be done while negotiating the twisted and convoluted plots of the vampires as Bianca, an old enemy, rises within their ranks.
It's a desperate fight to keep body and soul together – and to protect those he cares about who are being targeted by forces even Harry can't comprehend.