In the midst of setting up their undersea headquarters, Aquaman & Aqualad are suddenly beset by strange occurrences. The culprit is revealed to be Quisp, a self-described Water Sprite, from a "secret sea beneath the ocean." Quisp has come to warn Aquaman of an impending peril to his world. A trio of colossal Fire Trolls have broken free of a volcano, through a fissure in Quisp's world. The fissure extends into Aquaman' s world , as well. No sooner has Quisp explained the threat, when the Fire Trolls emerge. Aquaman, Aqualad & a pod of sperm whales rush to engage the Fire Trolls, but are unable to slow their ascension to the surface. Racing ahead on dolphin back, Aquaman, Aquald, & Quisp reach the Fire Troll's destination first., a jungle island, housing a U.S. army missile base, still under construction. A pitched battle ensues, with Aquaman joining the military forces in, unsuccessfully, trying to repel the invading Fire Trolls. Aquaman rationalizes that intense cold may be the downfall for the Fire Trolls, & with Quisp's help, races to the mainland atop a great waterspout, to retrieve the necessary chemicals.
Aquaman returns to find the Fire Trolls ransacking the army base. With only a small amount of the freezing chemical at his disposal, Aquaman quickly realizes that the Fire Troll's immense size limits the effectiveness of the icy spray. The attacked Fire Troll brushes the chemical from it's gargantuan hands, raining the droplets down on Aquaman & Aquald. The pair feel their limbs go numb with cold. Acting fast, Quisp uses magic to shrink the heroes down, just in time to evade being crushed by the Fire Troll's rapidly descending fist. The impact hurls Aquaman & Aqualad into the surrounding jungle. Suffering from the onset of water deprivation, the pair realize that at their reduced size, they'll die before they can reach the ocean. Foraging for a source of water, the pair narrowly escape from an attacking scorpion. An abandoned jeep promises the possibility of water, if they can just reach the radiator. After fending off a hungry lizard with a pair of wire snippers, Aquaman & Aqualad use the tool to help them in opening the radiator cap. To their great despair, the radiator is empty.
Spying a passing pelican, Aquaman attracts the birds attention, then beans it with the radiator cap. In it's indignation, the pelican drops the fish it was carrying, simultaneously releasing the mouthful of ocean water it collected, scooping up the fish. Re-invigorated by the sudden deluge, Aquaman & Aqualad leap inside the radiator to escape the angry pelican. After it departs, the duo make there way back to the coast line, slowly returning to their normal size. The Fire Trolls have left the island. Quisp brings the heroes up to speed. The purpose of the Fire Troll's raid on the army base was to steal all the missiles, which they then stockpile beneath the waves. Their intention is to steal all the world's missiles, use them to destroy all the undersea volcanos, thus releasing all imprisoned Fire Trolls. As an added bonus, the destruction of these volcanos will open fissures around the globe, releasing heat from the Earth's core to the surface, creating a world wide inferno that the Fire Trolls will rule. After being chastised by Aqualad, Quisp reveals that he did not use his magic to shrink the heroes, but was, instead, attempting to repel them from harm's way, while they were frozen. Suddenly, Aquaman has a plan. Quisp taunts the Fire Trolls, leading them up from the depths & back to the island. Aquaman sprays the monstrous trio with the last of the freezing chemicals. Then, Quisp focuses his repelling magic on them. The Fire Trolls are reduced to three inches in height. Aquaman has correctly surmised that it was the combination of the freezing solution & Quisp's magic that created the shrinking effect. Quickly, Aquaman, Aqualad & Quisp return the miniaturized Fire Trolls to their volcanic prison, & then with the help of a pod of sperm whales, fill in & re-seal the fissure, imprisoning the Fire Trolls forever. Quisp returns to his home, but promises to return in the near future.