In the "Big Trench", Aquaman and Aqualad encounter the sinister marauders who have been raiding Atlantis' mines. The raiders draw on, then fire at the two heroes, knocking them from their mounts. As the raiders close in for the kill, Aquaman presses a stud on his belt that remote activates the ore tram, sending it barreling into the raiders. Aquaman and Aqualad leap back in the saddle to pursue the raiders, who are drawn back to their ship via magnetic waves. The raiders' ship is much faster then the sea horses, so Aquaman switches over to the tram hauling sea sled, minus all the ore cars. Just as the Aquatic Aces are about to catch the raiders' ship, it suddenly vanishes. Aquaman floods the waters where the ship vanished with marker dye, then collects the colored ocean water in the sea sled's mineral dust vacuum. Hauling it back to Atlantis, Aquaman has his chef scientist, Vulko, run every test imaginable on the water. Vulko's tests turn up nothing out of the ordinary, however, by chance, a single droplet spills out onto the magnifier lens, revealing the raiders' ship. Realizing his foes originate from a microscopic world, Aquaman calls in the Atom.
The Atom journeys to Atlantis, but before he can arrive, Aquaman is drawn into the raiders' microscopic world by a strange bean emanating from the water droplet. Vulko provides the Atom with a pill that will allow the Tiny Titan to breathe underwater for several days. Once consumed, the Atom follows Aquaman into the water droplet world. After a narrow escape from a hungry microscopic organism, the Atom encounters the raiders' ship. Stealthily boarding it, the Atom follows the raiders back to their secret lair. The raiders present themselves to their master, Galg, a horrifically mutated form of plankton. Galg's sensors have detected the Atom's presence in his citadel, thus the raiders are tasked with searching for the microscopic intruder. The Atom follows Galg into another chamber, however, anticipating such an action, Galg is able to trap the Atom in a beam of light. With the Atom held fast, Galg reveals that Aquaman, too, is his prisoner, englobed in a diatomic cage composed of living plankton. The Atoms shrinks so small as to be invisible to the naked eye. Believing the Atom to have escaped, Galg turns off the light beam that was, in fact, still holding the Atom.
The Atom sets about to freeing Aquaman, however, anticipating that course of action, Galg stimulates the growth rate of Aquaman's living cell. The Atom is suddenly in danger of being absorbed by the rapidly swelling organism. His one chance to escape is to reverse the size controls on his belt to grow. The Atom's quick expansion to "giant" size has the duel effect of freeing him, as well as destroying the plankton prison surrounding Aquaman. Impressed by the Atom's scientific acumen, Galg suggests an alliance. The Atom agrees on the condition that Aquaman be sent back to Atlantis. The Atom studies Galg's operation of the transmutation teleporter, that sends Aquaman back to his own world. With the Sea KIng safely out of Galg's clutches, the Atom attacks the monstrous plankton creature. Galg has anticipated the Atom's betrayal, however, and avoids the Atom's assault. When the Atom shrinks free from Galg's grasp, Galg begins sweeping the room with the teleport beam, attempting to enlarge his miniscule foe. The Atom leaps for Galg's cyclopian eye, blinding him with a well placed ink cartridge. Galg stumbles back into the teleport beam, and begins expanding. Galg materializes from the water droplet world, just outside of Atlantis, then explodes. The Atom rapidly returns to his "normal" six inches in stature, destroying Galg's machines in the process.