Okay, I thought about this idea for a long time now and I like to think of myself as a dialogue driven person over a scenery person (meaning I come up with better ideas for dialogue than I do creating an image but I will try my best.)
Anyways lets begin: The scene starts with a shot of Arkham Asylum at night it's raining. The camera starts at the front gate of Arkham and slowly works into the building. When the camera opens the door to the front room of the Asylum we see a receptionist talking to a guard "You're on Joker duty tonight, be extra careful he's been really quiet today." The guard takes a deep breath and mumbles "Shit, not tonight, please don't let anything happen tonight." The camera then follows the guard through the Asylum where we see a bunch of cells, people are screaming in the distance and all we hear besides that is the guards foot steps, the guard looks to the left to double doors with a key card lock on it, there are two signs one on the door stating (Authorized personnel only, danger beyond this point.) And one next to it that says "Violent and Dangerous Criminal Wing". The guard stops for a minute and then uses his card to open the door.) we hear "Access granted" And then the voice over "He may be dark, but I'm darker, he does things his way, and I do them mine. He is good and I am bad, He always wears a frown, and I think he should lighten up a bit, He wears a mask, and I took mine off a while ago, he fights crime, and I am the crime he fights...." The guard continues down the corridor walking past cells with names on the doors, he walks past The Penguin, and then, Two Face, and then he walks past The Riddler at which point a hand comes through the bars and a voice says "Riddle me this: He who laughs, won't laugh tonight, because he who laughs is enjoying night life." The guard jumps and puts his hand on his gun and notices a card in the hand of The Riddler. The hand turns over and a Joker card falls to the floor. "Well? Did you solve my riddle?" The guards eyes widen and he runs down the hall and looks through the cell door into an empty room. The wall has a hole in it and the camera slowly zooms outside. We no longer see the guard but we hear him call on his walkie. "He did it again, The Joker escaped! Full lock down!" Then we hear the alarm and shortly after we see the Bat signal in the sky. And we hear the voice again. "But above all else....*Giggle* I'm only joking." and then a giggle slowly turns into a laugh.
So, that's it.