The episode begins with Ren and Stimpy acting as the hosts of Untamed World, inviting the viewers to join them on an adventure on the island of Ignorania to discover the mysterious creature known as the “Lummox.” While exploring the jungle, they find evidence of the Lummox’s presence in the form of its droppings, which consist of old food remnants and discarded items like pizza boxes scattered on the ground. As Ren and Stimpy follow the trail of droppings, they come face to face with the Booger Red Lummox, a sloppy, overweight, and dimwitted middle-aged human. Excited by their discovery, Ren and Stimpy attempt to observe the Lummox closely, but their presence is accidentally revealed when Ren snaps a twig, attracting the Lummox’s attention. Feeling suspicious, the Lummox stares at Ren and Stimpy, prompting the duo to mimic the Lummox’s behavior in an attempt to blend in. They imitate the Lummox’s actions, such as digging in his nose, scratching his buttocks (though Ren refuses to do so), and playfully messing up his food, using a steak to comb his hair and smearing mashed potatoes all over himself. In a friendly gesture, the Lummox offers Stimpy a plate of purple giblets, to which Stimpy declines, explaining that he is a vegetarian. This refusal angers the Lummox, who becomes threatening and starts pounding his chest like a gorilla, ready to attack Ren and Stimpy. Quick thinking, Ren hands Stimpy a bucket of lard and coerces him into swallowing the entire contents to ward off the aggressive Lummox. After Stimpy successfully ingests both the bucket and the lard, the Lummox happily embraces them, referring to them as his “cousins.” He then leads them back to his log home, where the three spend their time together, watching television throughout the night. The next morning, Ren and Stimpy witness the arrival of a new Lummox, known as the Tree Lummox. Out of desperation to attract a mate, the Tree Lummox takes off his briefs and hangs them on a nearby tree. The Booger Red Lummox follows suit. Meanwhile, a female Lummox appears and must choose a mate based on the softness of their briefs. As the male Lummoxes anxiously observe, the female first selects the Booger Red Lummox’s brief, but ultimately decides it is not up to her standards. Finally, she chooses the Tree Lummox’s brief, which she deems perfect for her mate. This infuriates the Booger Red Lummox, who becomes jealous of his rival and challenges him to a battle for the affections of their mate. The battle begins with the Tree Lummox performing a belly wave, followed by the Booger Red Lummox shooting an ink pen from his bare tummy into the Tree Lummox’s face. Ultimately, the two engage in a belching contest. The Booger Red Lummox starts by burping the ABCs, and the Tree Lummox responds by burping the word “Godzilla.” Finally, the Booger Red Lummox delivers a burp that mimics Abraham Lincoln’s famous speech. Unfortunately for the Tree Lummox, the Booger Red Lummox emerges victorious, earning the right to have the female Lummox as his mate. She models around him, before ultimately walking away. The episode concludes with Ren and Stimpy back in their office, where Stimpy playfully blows raspberries through his sandwich to attract the attention of the Lummoxes, who engage in a bear hug.

On their way back to Mauville City, Ash and friends travel through the Valley of Steel, home of many different kinds of Steel Pokémon and a potential shortcut to Mauville City and then Petalburg City. On their way through, they come across a Torkoal being attacked by several Steel Pokémon. After using Pikachu to scare the Pokémon away, the Fire-type hears a noise, also scaring it off. Later, having reunited with Torkoal, Ash and friends become determined to help Torkoal defeat the Steelix that lords over the valley. Will they succeed in cutting through the valley unharmed or will the angry Steel-type block their way?

Trakeena informs Furio that his time is running out, he needs to find the Lights of Orion for Scorpius to avoid his imminent destruction. Furio agrees to join Trakeena to succeed in his plan. For Furio's lack of luck, the cave where the lights are hidden is impenetrable and only someone considered "chosen" can enter the cave and gain access to the interior. Furio believes he knows someone suitable for this job. Some time later, Furio and Trakeena attack Maya and Kendrix with a group of Stingwingers, the girls are unable to defeat the group alone and soon they are immobilized, the other Rangers appear soon after mounted in their Astro Cycles and shoot against the Stingwingers releasing the Pink and Yellow Ranger. After this, Furio and Trakeena present a fake magic show revealing a great mysterious box and when opened to the surprise of the Power Rangers, Mike Corbett appears unconscious in the box. Leo and the other Power Rangers try to rescue Mike, but are prevented by the Stingwingers from approaching the villains, quickly Trakeena and Furio close the box containing Mike and flee the place in a vehicle. Leo follows the vehicle of Furio and Trakeena and some time later finds them in the forest keeping Mike chained in a still unconscious tree. Damon and the other Rangers distract Furio and Trakeena while Leo seizes the opportunity to rescue Mike. When Mike regains consciousness, he explains to Leo that Furio is searching for the Lights of Orion, powerful sources of energy that can never fall into the hands of Scorpius, as this would pose a great danger, he convinces Leo to open the cave. Leo is able to release the entrance to the cave, but when he picks up a locked box hidden inside here, surprisingly, Mike attacks him in the back, knocking down Leo and stealing the object from his hands. Soon after, Mike appears on the battlefield in possession of the stolen box that presumably contains the Lights and reverence Furio, the Rangers are incredulous with the possibility of Mike have betrayed them. So he reveals his true identity, in fact he was not the real Mike, but Mutantrum, a Scorpius monster who took the human form of Mike just to fool and convince Leo to open the cave and thus have access to the object to be delivered to Furio. Leo confronts Furio, preventing him from opening the box and the other Power Rangers invoke the Galactabeasts to fight the giant Mutantrum, the monster is soon defeated by the Galaxy Megazord. On the other hand, Leo makes a violent fight against Furio in the attempt to rescue the box and prevent it from being opened, but Furio ends up opening the box that, to his desperation, is empty. Trakeena is furious and threatens Furio saying that he will be punished by Scorpius because of this. On the Scorpion Stinger, Furio begs a new opportunity from Scorpius, who in turn grants Furio one last chance, obeying a request from Trakeena, threatening to destroy him if he fails again.

Open with the Turtles, April, and Casey as they set off on a rafting trip. Leonardo is still brooding in silence. The group floats down the river and passes an old nuclear power plant. Casey states that he heard that this plant is in the process of being shut down and Donatello notes that most of them aren’t safe. As our heroes continue to float past the plant, they are unaware of a group of mysterious fins in the murky water swimming by them. The camera switches to an underwater view and we see that these aren't fish - but some kind of humanoid fish-men - with big, sharp claws! The group has made camp for the night and they're sitting around a fire telling jokes. Leonardo is off by himself, surveying the river absentmindedly, obviously lost in his own thoughts. April notices that her friend is still troubled, and goes over to him to see what's wrong. Leonardo explains that he feels like a total failure considering how poorly their last battle with Shredder went. Suddenly, a fish-like humanoid comes ashore and collapses. It’s a Merwoman, and she's not breathing! Casey and April try to perform CPR, but this is cut short as four Mermen emerge from the river and attack, thinking that our heroes are hurting the Merwoman. The Turtles must fight back to allow April and Casey time to help the Merwoman. As the Turtles battle, they are pulled into the murky water, leaving Casey and April alone with the dying Merwoman. Suddenly, April is drawn into a trance by the Merwoman and sees the entire history of her species. This Merwoman is the last female of her kind, the four others are the last males. She telepathically explains to April how her people are very long-lived - indeed, she was a child back when the Mermen were slaves of the Y’Lyntians. Eventually, there was a revolt (see Episode #68) and the Y’Lyntian island sank, freeing the Mermen. The fish people spent many wonderful years living off the land, but over time, human society populated the planet, leaving little room for the fish people and thus they have been slowly dying off. The Merwoman also explains how she has been left on her own to tend the last eggs of her species, an arduous task which leaves her exhausted. Unfortunately, she fell asleep on the shore by the nuclear power plant and suffered radiation poisoning. Meanwhile, the Turtles continue their underwater skirmish with the four Mermen. The tide of battle goes back and forth, with Raphael finally breaking free, and helps his brothers take down the others. Back on shore, the Merwoman suddenly sits up and grasps April's temples. O'Neil is drawn further into the trance, and discovers that the eggs are in the path of the toxic waste leaking from the power plant - if something isn't done, the eggs will be destroyed, and the Merman will become extinct! With her warning told, the Merwoman collapses and dies. The fight beneath the waves continues - but the Mermen sense that their woman has passed, break off their attack and surface. The Mermen carry the last female of their species into the water and push her into the current. The males then solemnly swim off on their own. Our heroes started to mourn the death of Merwoman, until April realizes that they will be the last of their kind (just like the Turtles) unless they do something to save the eggs! The group searches the area for the place in April's vision, and they approach the nuclear power plant. Don uses his equipment and discovers that the plant is leaking toxic waste directly into the river - and worse yet, a nearby dike is about to collapse, which will send all of the deadly poison into the stream. April realizes that the eggs are stored near the dike, so something will have to be done to stop it from breaking. With an entire species on the line, Don quickly thinks of a plan to block the contaminated water. The Turtles and Casey sneak into the plant - Casey, Raph, Leo, and Mike will distract the workers, giving Donatello the chance to complete his mission. Don will redirect the explosive charges set to destroy the tower in order to have it fall into the stream, where it will hopefully dam the toxic waste. Raph sets off the plant's alarms and the guards leave their work on the tower to find the intruders. Don enters the abandoned structure and is able to re-route the explosives. Raph, Leo, Mike, and Casey make their escape - but Don isn't answering his Shell Cell. Unfortunately, the brainy ninja has run into a burly worker, who attacks him. Don wins the fight easily, but the explosives are about to go off. The Turtle tries to carry the man to safety, but he's too heavy. With only seconds left to escape, Leonardo arrives and helps his brother carry the man to safety, just as the charges ignite and the tower collapses! Don set the explosives perfectly, and the rubble has successfully blocked off the stream full of toxic waste. The Turtles, April, and Casey safely escape as a pickup truck pulls up.