In a "Fantastic Voyage" like adventure, Atom shrinks Batman and Wonder Woman so they can enter Superman's bloodstream and destroy a lethal nanite virus.
As Lex Luthor in his battle suit rampages through S.T.A.R. Labs, he brushes aside the guards who have fired at him. But first Batman and then Wonder Woman intervene to try to stop him. Luthor distracts them by causing the roof to collapse, flying through the hole he made to escape. Outside, up in the air, he encounters Superman but, as an apparent distraction, he fires a missile that starts to spread a suspiciously green gas across the city below. Superman flys down and sucks it all in without suffering any ill affects and then flys out into space and exhales it. He comes back down to where Batman and Wonder Woman have cornered Luthor but becomes dizzy and collapses onto the Batplane. Wonder Woman holds Superman as Luthor flys off.
Having taken the stricken Superman to the Watchtower, Batman and Wonder Woman join Atom and Red Tornado to monitor Superman's state. Red Tornado observes that his vital signs are dipping, and Atom discovers that this is due to a swarm of nano-bots that have infested Superman's heart and are feeding off his special energy. Further, there is also a queen present that is rapidly reproducing more nano-bots. Atom says that they will have to go inside Superman's body to surgically remove the infestation.
Atom, Batman and Wonder Woman don suits and helmets to enable them to survive inside Superman's body and Atom tells the other two he can shrink them for thirty minutes. The three shrink down and enter Superman's nostrils where Batman decides they should enter the bloodstream via the sinuses and the lungs. Eventually, in the heart, they see the nano-bots surrounding the machine that collects the energy and do battle with them, destroying them. Further on they encounter the queen who turns and flees while the threesome go in pursuit.
Elsewhere, Luthor, following the progress of the nano-bots, notices that Superman is recovering. Flying over to the Watchtower, he bursts in and, after a fight, disables Red Tornado. He finds Superman's unconscious body and attacks it with a kryptonite ray. Detecting this, Atom decides to return to deal with Luthor. Batman and Wonder Woman destroy the queen after a lengthy struggle by allowing it to be digested by the immune system and, with only seconds left, make for the nostrils. Atom, flying out of the mouth, knocks the ray gun out of Luthor's hand and fights him. Behind, Superman is sitting up and, when he sneezes, Batman and Wonder Woman fly out at full size and flatten Luthor
Appearing in “Inside Job“