I recently read Dead Beat by Jim Butcher, the seventh novel in the Dresden Files. Harry Dresden is Chicago private detective and professional wizard, struggling to make a living and control the powerful magic he wields. Dead Beat is set three days before Halloween when Märvra, vampire Queen of the Black Court and Harry’s enemy, blackmails him into finding an elusive text by necromancer Kemmler. Racing against time to find Kemmler’s text before the end of Halloween, Harry discovers Kemmler’s followers are intent on performing a rite on Halloween gifting god-like powers over life and death to the one conducting rite. The Dresden Files contain meticulous world-building with Machiavellian power struggles between fairy and vampire courts, the White Council of wizards and many unaffiliated supernatural beings.