Batman: The Long Halloween is a 13-issue American comic book limited series written by Jeph Loeb with art by Tim Sale. It was originally published by DC Comics in 1996 and 1997. It was the follow-up to three Batman: Legends of the Dark Knight Halloween Specials (which were reprinted in Batman: Haunted Knight) by the same creative team. The series' success led to Loeb and Sale to reteam for two sequels, Batman: Dark Victory and Catwoman: When in Rome, which are set concurrently. 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 City'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. In continuity terms, The Long Halloween continues the story of Batman: Year One for the characters of Batman, Gordon, Catwoman, and Falcone, and is considered to replace the earlier effort Batman: Year Two in the character's continuity. It also revolves around the transition of Batman's rogues gallery from plainclothes, real-world style mobsters to full-fledged supervillains and tells the origin of Two-Face, incorporating elements of the story in Batman: Annual #14. Source: Wikipedia (en)