Issue 146
Batman: Legends of the Dark Knight (1989-2007) #144
Thanks to Ra's al Ghul, the Joker is about to put his master plan into action: the release of a Joker-gas bomb that will decimate the entire planet. Of course, Batman will eventually stop the two—but that's only if Joker and Ra's don't kill each other first! 'The Demon Laughs' part 3.