Two years ago, Batman and the second Atom (Ray Palmer) worked together to save themselves from villains like Cannoneer and Thinker. Ray later retired and Ryan Choi takes up the mantle. Two years later, Palmer's arch-nemesis Chronos plans an attack and Batman goes looking for him. When Batman disappears, Aquaman and Atom (Ryan Choi) must shrink to a microscopic size in the Amazon Jungle to save the Caped Crusader and Ray Palmer from tiny aliens.