If you head on over to the teaser site for The Joker, whysoserious.com you will see a flash image of a pumpkin. Now many so far have been thinking its simple because its Halloween time... well not many know but the "sequel" of sorta to Batman: Year One, which Batman Begins was based on, is called The Long Halloween. Which the cover for looks like this.See the pumpkin on the cover? Yep. The Dark Knight will be a film version of The Long Halloween, although I doubt it will be DIRECT from this comic, since this comic series features damn near every baddie from Batman. So since I am lazy and don't wanna type up exactly what goes down in this series, I found it all on wikipedia. Beware as there might be spoilers ahead. Dont worry Ill let you know when you are headed into spoiler territory.
The Plot: The Long Halloween is heavily influenced by film noir and films such as The Godfather. The series continues the story of Carmine Falcone introduced in Frank Miller's Batman: Year One / Batman Begins. Set early in Batman's career a few months after the events of Year One, the story revolves around the gradual transition of Batman's rogues' gallery from simple mob goons to full-fledged supervillains. It is also the origin of Two-Face, adding along to the story in Batman: Annual 14. It follows the events in a few months following Year One and examines an entire year of Batman's career as a crime fighter, so it could be considered a "Year One"/"Year Two", in some form. This story has been accepted into continuity after Zero Hour erased the events of Batman: Year Two from the canon. The plot follows Batman's struggle to find a mysterious killer, while Harvey Dent's and Jim Gordon's marriages are strained during the process. As the story unfolds, Carmine Falcone hires "freaks" (Poison Ivy, the Riddler, the Scarecrow, and the Mad Hatter) in an attempt to stop the Batman and restore power back to the family, only to discover that the freaks are more powerful than he expected.
The Story/Spoilers: As Batman, Captain Jim Gordon, and District Attorney Harvey Dent collaborate to legally bring down Carmine Falcone, a series of mob-related murders begins. The mystery villain (eventually nicknamed Holiday) is killing mafia members affiliated with Falcone on holidays, leaving behind related tokens as a calling card, as well as the murder weapon: a .22 caliber pistol with a baby bottle nipple for a silencer.
Valid clues are few and far between, as the killings appear to be the work of a professional. Batman and Gordon turn to another holiday-themed criminal, the incarcerated Calendar Man, for insight. The evidence and rumors eventually pile up against Harvey Dent himself, who faces mounting stress at home with his troubled wife Gilda, and in his professional life. Gilda just wants to settle down and have a child with him, but Harvey is determined to solve the mystery of the Holiday Killer before taking a rest. At the same time, Bruce Wayne attempts to have a relationship with Selina Kyle, whom he does not yet realize is also the anti-hero/thief Catwoman. His own dual identity, which he finds hard to balance between the two, is a major obstacle to any kind of romantic happiness with her.
Carmine Falcone, aware that his empire is no longer as untouchable as it once was, begins employing supervillains (referred to by nearly every other character as 'freaks') in his war against Batman. Poison Ivy is hired at one point to sway Bruce Wayne into green-lighting Falcone's attempt to launder money through the First Bank of Gotham; a move that Wayne was firmly against. The Riddler is asked to find the identity of Holiday, and Falcone also hires Scarecrow and the Mad Hatter to rob the City Depository.
As the Holiday killings continue; outrage grows on the parts of our heroes, the mafia, even the Joker who resents sharing the limelight. Falcone is devastated when his own son, the estranged Harvard-educated Alberto, is murdered on New Year's Eve and his body is lost in Gotham River. Harvey faces suspicion from all sides as the lead suspect in the Holiday murders. He continues mounting an offense on the Roman. Sal Maroni, a major competitor of Falcone's criminal empire, agrees to testify against Falcone in exchange for leniency. Vernon Field, Dent's bookish, nerdy assistant, is bribed by Maroni's men and agrees to deliver something to Maroni in court. Maroni's day in court arrives (on Falcone's birthday), and he splashes Vernon's acid in Dent's face. Dent's face is ruined, and his mind cracks in two. Later that night, Dent escapes from the hospital into the sewers, where he befriends Solomon Grundy.
While in police custody, Maroni is murdered by Alberto Falcone, as he is transported to another holding cell. Alberto reveals himself to be Holiday; he faked his own death and had been working on his father's behalf ever since. Batman is already present, disguised as a SWAT officer, and beats Alberto within an inch of his life before Gordon arrests the Holiday killer. In custody, Alberto reveals his motives for the murders; his birthday was Valentine's Day, and his father was always too busy to spend time with him. The Holiday murders were Alberto's way of 'making time' for his father and to gain acceptance into the family. Before the end of the series, Alberto is sentenced to the gas chamber. Unused pages seen in the TPB of The Long Halloween show Alberto in Arkham asylum, having been deemed insane by the courts, but these pages weren't used due to space constraints. They were instead shown in the follow-up sequel: Batman: Dark Victory
In the Halloween climax, Falcone is accosted in his home by the entire Rogues Gallery of villains, including the Joker, Catwoman, Solomon Grundy, Poison Ivy, the Mad Hatter, Scarecrow, and the Penguin (making his first and only appearance in The Long Halloween). The group is led by none other than Two-Face, formerly Harvey Dent. Batman arrives on the scene and dispatches all but Catwoman and Two-Face. Harvey murders Falcone, Holiday-style, in front of his mobster daughter Sofia Falcone Gigante. She is enraged and attempts to attack, but gets tangled up with Catwoman and ends up throwing Catwoman and herself out a window. Catwoman survives unscratched, but Sofia is not so lucky (she returns in Batman: Dark Victory and figures prominently).
Two-Face surrenders, having done what he intended to do (he killed Vernon in revenge earlier that same night). Before being sent to Arkham, he cryptically tells Gordon and Batman that there were two Holiday Killers. They infer that he meant himself, having killed Falcone on Halloween. Batman and Gordon accept that their friendship has changed, but they still have work to do. In the coda, Gilda Dent is planning to leave Gotham City forever. In the final revelation of the series, she explains to an unpresent Harvey that she was the first Holiday Killer. She also explains her reasons for becoming the Holiday Killer - she wanted to free Gotham City of its criminal menaces, so that her dedicated husband could spend more time with his family. She also theorizes that Harvey himself took the same path for similar reasons. She used his files as District Attorney to learn what she needed to know, and was unaccounted for at the time of the murders. When Alberto faked his own death on New Year's Eve, she simply let him take over and had nothing further to do with it. She disposes of the incriminating trenchcoat, fedora, and last .22 pistol by throwing them into the furnace.
Closing Thoughts: Obviously they're not having all these villains in The Dark Knight, my guess is just The Joker, Scarecrow, and Harley Quinn will be involved. Unless they kept things seriously under wraps. Either way, this movie is going to kick major fuckin ass.