Some of it came from, we like to do a lot of playing around with doubling on the show, you know? Also like a scene from the books. We wanted to keep on playing with the ideas of the Joker, and also ways of telling the audience that Jerome is not our Joker -- not The Joker, even if he was our Joker -- or that he's doing another version of The Joker on the show who's also not The Joker. [laughs] But the idea was: Jerome, as chaotic and anarchic as the acting can be, doesn't embody all of the qualities that would go on to eventually be The Joker. So we asked ourselves how could we take some of those qualities and embed them in another character, and the most obvious way to do that was to give Jerome a twin brother. So in creating Jeremiah, we wanted to give him [pieces from] different books, like the idea that he and Batman are paired together in a way, whether they're like brothers or two sides of the same coin -- whatever you want to say. So giving that to Jeremiah, creating a psychosis where Jerome is not the brother he should have had, but that Bruce is the brother he should have had. So he gets to entertain whether he wants to drive Bruce insane, which gave us the opportunity in tomorrow night's episode to play our version of The Killing Joke, which you can see in all the iconography whenever you watch the episode. In 'One Bad Day,' rather than trying to drive Gordon insane as in does in [Alan] Moore's book, here he's trying to drive Bruce insane so the two of them can be paired together.