Patrolling the high seas, Aquaman and Aqualad spy a ship on the horizon that is floating above the water. Nearing the strange phenomena, they see that it is their friend, the water sprite, Quisp, who is magically levitating the vessel. Seeing their approach, Quisp speeds off with the ship, ignoring Aquaman's attempt to make contact. Aquaman and Aqualad pursue the impish prankster. Quisp splits the ocean wide open before them. Aquaman and Aqualad are swimming too fast to stop their plunge into the watery crevasse. In the time it takes for them to recover, Quisp has made good his escape. Aquaman and Aqualad are quick to pick up Quisp's trail. Soon enough they re-encounter him, this time making off with a large barge. Launched into the air on the twin water spouts of two sperm whales, Aquaman and Aqualad are able to surprise Quisp and catch hold of him. Only for a moment, though, as Quisp's magic catapults the sperm whales into the two heroes. The impact renders them both unconscious. Quisp escapes again. Still stunned, Aquaman and Aqualad are too groggy to swim out of the path of an ocean liner, bearing down on them. The pair are rescued by Quisp. Faced with Aquaman's accusations of wrong doing, Quisp swears that he was not involved with the morning's activities. The culprit was , in truth, Quisp's twin brother, Quink. Quisp is reluctant to believe that his brother would engage in criminal activities. Quisp follows the heroes to a nearby island to get to the heart of the mystery. The missing ships are all berthed on the island, under the watchful eye of the notorious pirate, Captain Slade. Aquaman is about to take Captain Slade into custody, when Quink ambushes the heroes, including his own brother, Quisp.
Only momentarily stunned, Aquaman and Aqualad are quick to run down Captain Slade, tackling him out of his speedboat and into the ocean. Captain Slade wrests himself away from the two heroes, who are then attacked by both Quisp and Quink. Aquaman and Aqualad are slow to recover form the double magical assault of the two water sprites. When they do come to, Quisp explains that he had used his magic to deflect the worst of his brother's magic away from Aquaman and Aqualad. Suddenly, two enormous sea creatures from Quisp's hidden world beneath the waves, break the surface. Quisp postulates that the creatures must have followed either him, or Quink, into Aquaman's world. Docile underwater, the monstrous crustaceans go berserk on the surface. Aquaman instructs Aqualad to continue the search for Quink and Captain Slade, while Aquaman and Quisp try to intercept the marine beasts before they can reach the mainland. Arriving too late, Aquaman and Quisp mount the best defense they can in the face of the creature's rampage through a coastal town. Quisp's repelling magic is able to keep the beasts from harming any civilians, long enough for Aquaman to crash a milk truck into them. The flow of released milk over the creatures soothes them long enough for Aquaman and Quisp to get them back underwater. Meanwhile, Aqualad has caught up with Quink and Captain Slade, sending word to Aquaman via signal fish. Captain Slade, though, has spotted Aqualad and sends Quink to deal with him. Quisp arrives just in time, placing himself between Quink and Aqualad, finally able to confront his errant brother. Quink explains that he has come to Aquaman's world in pursuit of the water sprite criminal, Quirk. Quirk had been rumored to have allied himself with a marauding raider, one that Captain Slade had helpfully identified as being Aquaman. Quisp sets his naive brother straight, & orders him to return to their world, along with the Borer Beast and Crusher Beast that had followed him up. Aquaman, Aqualad, and Quisp resume their pursuit of Captain Slade. The find him, standing outside of an abandoned lighthouse, on a small islet. The criminal, Quirk, is by his side.
Quisp and Quirk square off against one another, but are too evenly matched for either to gain the upper hand over the other. A passing helicopter drops a weird weapon into Captain Slade's hand. With it, he's able to rob Quisp of his magical powers. With no defense against Quirk's magic, Aquaman, Aqualad and Quisp are easily defeated. Captain Slade boasts that the strange gun literally fell into his lap, dropped from a passing spaceship. Upon their first encounter, Captain Slade and Quirk were startled by one another and quickly attacked each other. Quirk lost his all his magical abilities, but Captain Slade's gun was damaged. Captain Slade set about to having the gun repaired, while Quirk waited for his magic abilities to return. The two were quick to strike a bargain. Quirk would help Captain Slade loot the high seas. In return, Captain Slade would give Quirk the gun. Quirk could then return to his world, rob all the other water sprites of their magic abilities, making him all-powerful in his world. They're just about to imprison Aquaman, Aqualad, & Quisp in the lighthouse's dungeon, when a giant manta ray sweeps the heroic trio into the sea. Captain Slade & Quirk go on to loot another cargo ship. Midway through the crime, Quisp arrives, traveling atop a giant water spout. Captain Slade fires his weapon at Quisp. No effect. He fires again to no avail. Believing the weapon is no longer capable of stealing a water sprite's magical abilities, Quirk is quick to dissolve his partnership with Captain Slade. Aquaman leaps aboard Captain Slade's speedboat & wrests the gun from his grasp. Captain Slade begs Quirk to save him. Bearing no love for Aquaman, Quirk readies an attack. Aquaman blasts Quirk with the ray gun. Much to Quirk's surprise, his abilities vanish. Aquaman reveals that while Quisp did lose his abilities again, when Captain Slade fired upon him, it was actually Quink who was creating the water spout that Quisp was riding atop. Quisp returns all the plundered loot back to the various cargo ships that Captain Slade targeted. Aquaman and Aqualad take Captain Slade into custody, while Quisp and Quink return to their world with Quirk.