The Joker is dead. There is no doubt about that. But whether Batman finally snapped his scrawny neck or some other sinister force in Gotham City did the deed is still a mystery.Problem is, Batman can't remember…and the more he digs into this labyrinthian case, the more his mind starts to doubt everything he's uncovering. So who better to set him straight than…John Constantine? Problem with that is as much as John loves a good mystery, he loves messing with people's heads even more. So with John's “help,” the pair will delve into the sordid underbelly of Gotham as they race toward the mind-blowing truth of who murdered The Joker.