"Death in the Family, Book 4 of 4: Chapter 6"
The Joker has murdered Jason Todd after Jason's revelation that his mother wasn't the woman he thought she'd be. The Joker's also been named ambassador to Iran, and when Bruce Wayne attends the Joker's acceptance speech to the world he has to remember diplomatic immunity renders Joker untouchable. Or does it? Will the Joker pay for Jason's death?