Title: Cold Days
Author: Jim Butcher
Genre: urban fantasy

Chicago's favorite wizard/detective is back although he has been "promoted" to Mab's Winter Knight. After coming back from the dead and enduring Mab's version of physical therapy, Mab dispatches Harry on an impossible quest- kill an immortal. I can't give more details without venturing into spoiler territory, but as Harry returns to the mortal earth to carry out his "job," his friends show up one by one to help him. Karrin and Harry finally have a talk about their relationship (or lack thereof), Harry and Thomas trade brotherly insults, and Mouse even helps out. Pop culture references and sarcasm fill the pages as the danger mounts. Will Harry save Chicago while not succumbing to the dark dangers of being a Winter Knight?