After being transported through multiple dimensions alongside the rest of the new Batfamily, Terry McGinnis finds himself in need of help from countless other variants of Batman, who tell him about an oncoming crisis from the emergence of a variant of Bruce Wayne known only as "The Batman Who Laughs", a god-like being that is slowly but surely beginning to conquer the multiverse. Now, it is up to Terry and the others to stop this evil Batman before it is too late...
