Venusian bad guys plan on invading Earth, and Aquaman steps in to try and stop them.
Traveling from deep space to the deep sea, Aliena arrives on Earth. The target of her mission... Aquaman! The Sea King is located, traveling outside of Atlantis, with Aqualad and Mera. When Mera playfully upends Aquaman from his mount, Aliena sees an opportunity to sow dissent between the Atlantean KIng and Queen. As Aquaman pulls himself up off the sea floor, Aliena encases him in a hard water bubble, and hurls him into the mountain side. Aquaman, believing Mera responsible for his plight, cries out to his wife to end her prank before he's killed. Seconds before the bubble crashes into the mountain, Aliena physically pulls Aquaman from the bubble. In doing so, she herself is rendered unconscious. In actuality, she's merely feigning injury. Aquaman furiously confronts his wife over her shenanigans. Mera's protestations of innocence fall on deaf ears. Through tears, she departs the King's presence. Aqualad leaves to comfort her. Aliena "recovers", and tells Aquaman her tale. Like Mera, she, too, is from an extra-dimensional water world. An explosion of a substance called "Uritrium" catapulted Aliena into Aquaman's world. A large amount of the Uritrium came through with her, and it's radiation is, even now, beginning to kill her. She enlists Aquaman's aid in burying the Uritrium deep enough underground that she will be shielded from it's effects. To that end, Aquaman summons swordfish, sea turtles and whales to excavate the sea floor, then bury the Uritrium, 200 feet below the sea floor. In gratitude, Aliena kisses Aquaman, then returns to the underwater cave that serves as her base of operations on Earth. There she reports the success of her mission, and receives new orders.... kill Aquaman!
Aliena spies Aquaman swimming past an underwater volcano. Dropping strange pellets into the mouth of the volcano causes it to prematurely erupt. Aliena, however, gets tangled up in a mass of underwater flora before she can swim to safety. Aquaman is just about to swim clear of the exploding volcano, when he hears Aliena's cries for help. Doubling back, he frees Aliena from her floral entanglement, but the pair have no time to swim to safety before the volcano erupts. Aquaman summons sea tortoises to protect them from the burning debris and magma raining down upon them. Her life saved, Aliena has serious reservations about fulfilling her mission. The truth about Aliena's origin is a lie. In truth, she is an alien raider, in the service of Ka'Arl. Venusian authorities had placed the Uritirum on Earth, to thwart any designs Ka'Arl's raiders may have had on the planet. Aliena, at Ka'Arl's behest, duped Aquaman into removing the deadly Uritrium, thus allowing for Ka'Arl's incursion force to raid Earth. Aliena opts to lie to Ka'Arl about slaying Aquaman, when she meets him at the rendezvous point. However, the truth is quickly revealed when Aquaman descends on the alien landing site. Aliena confesses to Ka'Arl that she didn't have the heart to follow through with her orders. Ka'Arl sets about to killing Aquaman himself. Aquaman evades the alien's weapon's fire, maneuvering about in such a way that Ka'Arl's raiders take themselves out. Said action, though, leaves Aquaman in a position for Ka"Arl to draw a bead on him. Before Ka'Arl can get the shot off, Aliena shoots Aquaman herself, leaving the Sea King for dead.
Aqualad arrives in time to witness Aquaman's murder, but too late to prevent it. With vengeance in his heart, Aqualad takes off in pursuit of Ka'Arl and Aliena. Aquaman, surprisingly, recovers. Aquaman realizes that Aliena merely stunned him, an act which saved him from Ka'Arl's more lethal shot. He, too, takes off in pursuit of the raiders. Aqualad reaches them first, and hurls a coral spear at Ka'Arl. The spear is deflected by a passing fish, alerting Ka'Arl to Aqualad's presence. Ka'Arl levels his weapon on Aqualad, when an octopus swims between them, fouling the waters with it's ink. Aquaman has arrived. A pitched battle ensues between the Aquatic Aces and Ka'Arl. The alien raider fends off assaults from swordfish, before scoring a glancing shot on Aquaman. The Sea King is too stunned to evade Ka'Arl's kill shot. Just then, Aliena appears, holding the unearthed Uritrium. Exposure to the xenomineral's lethal radiation kills both Ka'Arl and Aliena. Aliena, having fallen in love with the Sea King, has sacrificed herself to save his life. The two heroes return to Atlantis.