Seriously, he should kill Rachel. Not becuase I hated Katie Holmes or her character, just that it would cement Batman's hate for the Joker. And I mean CEMENT.
Think about it: Joker kidnaps Rachel, who is now DA becuase her boss was killed(Harvey should come in as ADA), in her office and leaves a note for Batman to find. Bruce decides to visit her and bring her some roses, just for the hell of it. He finds her room a mess, with the note, written in green crayon, on the desk. He reads it and realizes that Joker kidnapped her. In the note, Joker tells Batman that he's kidnapped her and even where they are. Almost daring Batman to come and rescue her. In an abandoned circus or carnival. Batman alerts Gordon about the kidnapping, and then rides like hell to the circus. Inside the circus, Joker has armed all the attractions with deadly booby traps. Almost like a gauntlet that Batman has to get through. Each one getting harder and more deadlier. Batman than finally gets to The Hall of Mirrors, surrounded by images of the Joker and Rachel tied up and gagged in a chair. Then, the floor drops out from under Batman and a kind of chute leads him to and underground containment center, with a huge tank filled with murkey water.(I'm gonna borrow this part from Zaphod becuase it's an awesome idea) Joker is standing above the tank and to the side with a crane. Rachel is hanging from the crane tied up in the chair and gagged, hanging from the hook over the tank. Batman and Joker converse for a while, then Joker reveals that there's a Great White Shark in the tank. Batman then gives Joker and ultimatum. Take Batman in Rachel's place. Joker agrees and lets Rachel go. Batman whispers to Rachel to run out and wait for him outside when they pass each other. Joker ties Batman up and begins to drop him into the tank slowly, laughing the whole time. But Joker forgot to check Batman for things in his belt, becuase they've only met barely a few times before. So, Batman cuts himself free and disappears up the crane the whole time Joker is laughing and has his eyes off Batman. Then Joker is shocked and angry that Batman is gone, then Batman jumps down from the crane, wings spread onto the Joker. Then he proceeds to beat the crap out of him. Handcuffs Joker and goes outside to find Rachel. Joker uses some acid from his flower and eats through the handcuffs and follows Batman out, pulls a gun out of his coat pocket. Batman reaches Rachel and hugs her. They talk for a bit, then Joker calls after Batman, calling him Batsy. Holds the revolver up and shoots Rachel in the stomach, killing her almost instantly, her dying in Batman arms. Joker starts to laugh hysterically, Batman gets the most pissed he's ever gotten. Anger coursing through his veins. He sets Rachel down on the ground, and then proceeds to beat the hell out of the Joker, with intent of KILLING him. Hits him and kicks him and just beats the crap outta him. He starts to strangle him. Then a shot is fired from behind Batman and it hits the ground behind him, a warning shot from Gordon. He tells Batman to think about what he's doing. Just think about the whole exchange from Hush Vol. 1. Dent gets there shortly after Gordon does. Then, sirens sound from a distance. Batman is long gone by the time the cops show up. They arrest Joker, and carry Rachel away. Then, a few weeks later, Joker goes on trial, with new DA Harvey Dent prosecuting. Joker throws the acid in Dent's face during the trial, and thus is born Two-Face. Leading into the sequel.
Think about it: Joker kidnaps Rachel, who is now DA becuase her boss was killed(Harvey should come in as ADA), in her office and leaves a note for Batman to find. Bruce decides to visit her and bring her some roses, just for the hell of it. He finds her room a mess, with the note, written in green crayon, on the desk. He reads it and realizes that Joker kidnapped her. In the note, Joker tells Batman that he's kidnapped her and even where they are. Almost daring Batman to come and rescue her. In an abandoned circus or carnival. Batman alerts Gordon about the kidnapping, and then rides like hell to the circus. Inside the circus, Joker has armed all the attractions with deadly booby traps. Almost like a gauntlet that Batman has to get through. Each one getting harder and more deadlier. Batman than finally gets to The Hall of Mirrors, surrounded by images of the Joker and Rachel tied up and gagged in a chair. Then, the floor drops out from under Batman and a kind of chute leads him to and underground containment center, with a huge tank filled with murkey water.(I'm gonna borrow this part from Zaphod becuase it's an awesome idea) Joker is standing above the tank and to the side with a crane. Rachel is hanging from the crane tied up in the chair and gagged, hanging from the hook over the tank. Batman and Joker converse for a while, then Joker reveals that there's a Great White Shark in the tank. Batman then gives Joker and ultimatum. Take Batman in Rachel's place. Joker agrees and lets Rachel go. Batman whispers to Rachel to run out and wait for him outside when they pass each other. Joker ties Batman up and begins to drop him into the tank slowly, laughing the whole time. But Joker forgot to check Batman for things in his belt, becuase they've only met barely a few times before. So, Batman cuts himself free and disappears up the crane the whole time Joker is laughing and has his eyes off Batman. Then Joker is shocked and angry that Batman is gone, then Batman jumps down from the crane, wings spread onto the Joker. Then he proceeds to beat the crap out of him. Handcuffs Joker and goes outside to find Rachel. Joker uses some acid from his flower and eats through the handcuffs and follows Batman out, pulls a gun out of his coat pocket. Batman reaches Rachel and hugs her. They talk for a bit, then Joker calls after Batman, calling him Batsy. Holds the revolver up and shoots Rachel in the stomach, killing her almost instantly, her dying in Batman arms. Joker starts to laugh hysterically, Batman gets the most pissed he's ever gotten. Anger coursing through his veins. He sets Rachel down on the ground, and then proceeds to beat the hell out of the Joker, with intent of KILLING him. Hits him and kicks him and just beats the crap outta him. He starts to strangle him. Then a shot is fired from behind Batman and it hits the ground behind him, a warning shot from Gordon. He tells Batman to think about what he's doing. Just think about the whole exchange from Hush Vol. 1. Dent gets there shortly after Gordon does. Then, sirens sound from a distance. Batman is long gone by the time the cops show up. They arrest Joker, and carry Rachel away. Then, a few weeks later, Joker goes on trial, with new DA Harvey Dent prosecuting. Joker throws the acid in Dent's face during the trial, and thus is born Two-Face. Leading into the sequel.