Ghost Story by Jim Butcher

Ghost Story by Jim Butcher takes place in the Windy City, where Harry Dresden, the only wizard in the phone book, is dead. But even after dying (or is it just Purgatory?), Harry still has to save Chicago from evil wizards and mad ghosts. The thirteenth book in the Dresden Files series, this book continues Harry's struggles to protect his fellow Americans from the supernatural (or natural, if you think about the ages of Faeries, because they make human life look as short as bacteria).

Losing his powers and a physical body to house his spirit, Harry is rendered next to useless and cannot even defend himself. He would try to figure out what went wrong, but turns out that he can't escape an angry Queen of Faerie, especially the deal that they struck together...

WARNING: MATURE LANGUAGE. READER DISCRETION IS ADVISED.