Could be, that the Joker is taken to Arkham asylum, were he meets a young man that is soon to get out. He's very clean, and you can tell he's on his way to rehabilitation. At one point in time, the Joker sets down with the young man at lunch and begins to install the idea that he could take on the persona of the Joker, and "carry on the legacy". After many months, the young man becomes obsessed with the Joker and his world, its all he can think about. *montage of super imposed images of Heath's Joker setting at the interogation table in TDK, but now he's setting across from a young man in Arkham asylum.*
After sometime, the young man is relised, and as promised, takes on the roll the Joker. He just can't seem to catch a break when it comes to his crimes, but he has a real Joker vibe to him, his appears dirty and scrufy, giving him the apprearence of someone gone off the deep end. Many months later, little by little, he carves himself the old familiar Joker smile, but only on one side of his face. He begins to put clown make-up on in a cracked mirror. (With a very smeary quick motion) The surroundings are grim and dirty, and it appears he's in some sort of large run down facility's bathroom. There's blood, old and new on the floor.
The character's run however is breif, because just a few days after his "complete transformation", he plots to break the Joker out of Arkham, although his first attempts at being a "better class of criminal", over the many months of being on the street, and learning from his mistakes, he springs the Joker from Arkham. So many months ago the Joker had instructed the young man to bring him back to the large facility when he had broken him out of Arkham.
As the two enter the building, which is run down, some places are missing areas of the roof, and the walls are crumbling to bits. The veiwer can see "my father" carved in a "Jokerized" fashion on the wall, as the camera pans to the left following the two men. The young man opens a large door and enters another part of the structure.The young man walks into the large room, facing away from the Joker. As he does, the Joker keeps walking towards him.
Suddenly the Joker fingers a shelf near by, pulling a knife from it, he keeps walking towards the young man, coming from behind him, he stickes the blade to the side of his face missing the scar.
"You know, I had high hopes for you-you pulled through in the end, but, its-aah-time to, finish, what you started."
The Joker pulls the knife quickly, and the boy drops to the floor, blood evrywhere. The camera pans away from the two, and "a wife" is seen smeared onto the wall.
or something like that, LOL.