Taken by writer and artist Sean Murphy in "Batman: White Knight", Property of DC Comics
In this story, The Joker is chased through the streets of Gotham by The Batman in his Batmobile, destroying buildings and bridges in his pursuit of the Joker. Backed into a corner, the Joker takes out a container full of pills, claiming that he will never stop being The Joker unless he takes these pills. Without a second thought, Batman pins down The Joker and as he struggles, forces him to overdose on the anti-psychotic pills. This, however, lead to an unexpected result:The Joker becomes sane and completely free of his homicidal tendicies. The Joker, now going by the name Jack Napier,reunites with the original Harley Quinn and with her runs a campaign against the The Batman, saying that his methods only promote violence in Gotham and doesn't do anyhing except cause more chaos and destruction. The Batman, now seen as a villanous vigilante, must fight against Napier as everyone in his life begins to turn aginst him.
Taken by writer and artist Sean Murphy in "Batman: White Knight", Property of DC Comics