In the 2008 story arc "Batman R.I.P." the Joker is recruited by the Black Glove to destroy Batman, but betrays the group, killing its members one by one. After Batman's apparent death in "Final Crisis" (2008), Grayson investigates a series of murders (which leads him to a disguised Joker). The Joker is arrested, and then-Robin Damian Wayne beats him with a crowbar, paralleling Todd's murder. When the Joker escapes, he attacks the Black Glove, burying its leader Simon Hurt alive after the supervillain considers him a failure as an opponent; the Joker is then defeated by the recently returned Batman. In DC's The New 52, a 2011 relaunch of its titles following "Flashpoint", the Joker has his own face cut off. He disappears for a year, returning to launch an attack on Batman's extended family in "Death of the Family" so he and Batman can be the best hero and villain they can be. At the end of the storyline, the Joker falls off a cliff into a dark abyss. The Joker returns in the 2014 storyline "Endgame" in which he brainwashes the Justice League into attacking Batman, believing he has betrayed their relationship. The story implies that the Joker is immortal—having existed for centuries in Gotham as a cause of tragedy after exposure to a substance the Joker terms 'dionesium'—and is able to regenerate from mortal injuries. "Endgame" restores the Joker's face, and also reveals that he knows Batman's secret identity. The story ends with the apparent deaths of Batman and the Joker at each other's hands, though it is revealed that they were both resurrected in a life-restoring Lazarus Pit, without their memories. At the conclusion of the "Darkseid War" storyline, Batman used Metron's Mobius Chair to know the Joker's true name. The Mobius Chair revealed there "are three." Although a number of backstories have been given, a definitive one has not yet been established for the Joker. An unreliable narrator, the character is uncertain of who he was before and how he became the Joker: "Sometimes I remember it one way, sometimes another ...if I'm going to have a past, I prefer it to be multiple choice!" A story about the Joker's origin appeared in "Detective Comics" #168 (February 1951), nearly a decade after the character's debut. Here, the character is a laboratory worker who becomes the Red Hood (a masked criminal) to steal 1 million dollars and retire.