The Anti-Monitor (the Monitor's evil counterpart) is released into the DC Multiverse and begins to destroy the different Earths that compose it. The Monitor attempts to recruit heroes from across the Multiverse to fight back.
In one last final attempt to save the Multiverse, the Justice League join forces with other parallel versions of themselves to stop Lord Havok, who is now in league with the the Anti-Monitor, an unstoppable cosmic threat destroying the multiverse with waves of anti-matter.
