Batman: The Long Halloween
Publisher: DC Comics
Taking place during Batman's early days of crime fighting, The Long Halloween tells the story of a mysterious killer named Holiday, who murders people on holidays, one each month. Working with District Attorney Harvey Dent and Captain James Gordon, Batman races against the calendar as he tries to discover who Holiday is before he claims his next victim each month, while attempting to stop the crime war between two of Gotham's most powerful families, Maroni and Falcone.
This novel also acted as a re-introduction to the DC Universe for one of Batman's most elusive foes, Calendar Man, who knows the true identity of the Holiday killer but refuses to share this with Batman. He instead riddles and gives Batman hints from his Arkham Asylum cell. The story also ties into the events that transform Harvey Dent into Batman's enemy, Two-Face. Enemies such as Scarecrow, the Joker, Mad Hatter, Poison Ivy and the Riddler, among others, also make appearances