Skeletor and Quakke find a crystal on Denebria that makes Quakke stronger. Quakke tests his new strength on He-Man, Hydron, and Flipshot during their trip to get oil for the Vasionic Resonator on Denebria and they are saved by Sagitar.

During his fight with He-Man, Slush Head destroys the Trithuseum generators on Primus that prevents its core from overheating. The crystals needed to help power the Trithuseum generators upon its rebuilding can only be found in Gorn City on Denebria. He encounters the trader Meliac who Skeletor uses in his plot to defeat He-Man.

Adam is on trial for running away during an attack by the Evil Mutants and a supposed act of treachery when he was secretly transforming into He-Man with Werban prosecuting him. Despite Master Sebrian attempting to speak on Adam's behalf, Adam is found guilty by Werban and is to be shipped off to the Prison Moon for the next 18 Telks. Meanwhile, Skeletor and Flogg enlist their inside person to plant a disruption bomb at the Titus Observatory to serve as a diversion for the Evil Mutants' next attack.

The Galactic Guardians and the Evil Mutants remember their recent battle in the Quagmi Swamps. Each side recaps what happened during the battle.

An unbeatable gladiator champion named Dreadator is persuaded by Skeletor to fight He-Man. To prove that he is the best warrior in the universe, Dreadtor challenges He-Man to a duel.

Skeletor uses the Mind Lens to influence the human will. After causing damage on Primus, Skeletor wants to use the Mind Lens on He-Man.

A bug on the Starship Eternia causes it to land on Denebria. Sagitar rescues a Mutant named Felca who is the future bride of Slush Head. Discovering that Sagitar rescued Felca, Slush Head agrees to help the Galactic Guardians get a new part for the Starship Eternia. Flogg finds out that Slush Head invited the Galactic Guardians to his wedding as Skeletor sees this as an opportunity to get rid of them once and for all.

At the advice of Flogg, Quakke puts up bounty posters for He-Man's capture as the Evil Mutants and the Zeps look for him. He-Man frees some prisoners from Slush Head as they join up in his resistance. When Skeletor threatens a village, He-Man offers to surrender if they spare the village.

As the Scientists of Primus work on a way to deactivate the Zeps, Adam and Mara go to where Master Sebrian, Hydron, and Flipshot are being held and free them despite interference by Crita, Slush Head, and the Mutant Troopers. Afterwards, He-Man and Master Sebrian provide a diversion for Skeletor while Mara, Hydron, and Flipshot retake the Starship Eternia.

After the Galactic Guardians capture Quakke and B.H., the Scientists of Primus create a machine called the Mutator that can turn any human into a mutant. When it is tested on He-Man so that he can spy on Skeletor, it changes more than his appearance as destroys the Mutator and rescues Quake and B.H. Not realizing that the mutant is a transformed He-Man, Skeletor names him Cruncher and takes him in storming the Inner Council's chambers.

Master Sebrian and Mara crash land in a remote area of Denebria. When He-Man arrives on Denebria to save them, he encounters some friendly Mutants who claim that they were once humans.

Skeletor gets his hands on some anxiety gas which causes any males exposed to it to become trembling cowards and has an opposite on females. Now it is up to the females to defend Primus from the Evil Mutants.

Flogg has obtained some new laser cannons with their range being a threat to Primus. Now He-Man and the Galactic Guardians must infiltrate Nordor and destroy the cannons before it can be used on Primus.

At the advice of Skeletor, Flogg contacts Master Sebrian and gives Primus some Zeps as a goodwill gift for peace between Primus and Denebria. Once Primus is filled with Zeps, Skeletor and Flogg activate their remote that turns the Zeps into hideous beasts that attack the Primans. He-Man discovers that the Zeps are actually androids and that there are too many for him to fight all at once.

Primus has been taken over by the Evil Mutants and the Zeps. As He-Man and Mara have the key to the shield around Primus, Skeletor has captured Master Sebrian, Hydron, and Flipshot and sends B.H., Quakke, and Staghorn to find He-Man. Meanwhile, the Scientists of Primus work to find what makes the Zeps assume their monstrous forms.

Tricking the Scientists of Primus with an award that will be presented at a space station, Skeletor and Flogg use a robot to have them decode the formula for Energon. This substance is used to melt and destroy planets and the award given to them is filled with it. The only thing that can destroy Energon is a power that is as evil as Energon.

Skeletor uses a brainwave detector to help him find He-Man. When Skeletor abducts a spaceship, He-Man is nowhere to be found.

A large meeting of magic users is occurring on Primus. The Opague magician Ramlin is in attendance as he has a plan to steal everyone's magic.

Skeletor uses an intelligence amplifier given to him by Korac to enhance the intelligence of the Evil Mutants. Even when they succeed in overcoming He-Man, the Evil Mutants start being intellectually superior to Skeletor.

Slush Head captures the Scientists of Primus as they are working on repairing the Trithuseum generators. Upon learning that they built the shield around Primus, Skeletor sends them to the Quagmi Swamp in Denebria. He-Man, Hydron, and Flipshot head to Denebria to rescue the Scientists and get them back to Primus to repair the Trithuseum generators before Primus' core overheats.

Master Sebrian and Adam get a message from the Galactic Council's leader that they will meet on the planet Enoos. The same message meets Skeletor and Flogg as they plan to sway the Galactic Council to their side even by having B.H. fake a hit on Mara that Skeletor will save her from. When this works and the Galactic Council suggests that both planets send delegations, He-Man, Hydron, and Flipshot head to Denebria where they are led into a trap by Slush Head and Lizorr while Skeletor and B.H. secretly have a plan to have an explosive ore burrow into Primus.

Skeletor threatens to destroy Levitan if He-Man doesn't surrender. He-Man disguises himself as a Mutant Trooper to get close to Levitan while having a plan to retake Levitan and all of Primus with the help of the Galactic Guardians and the resistance. Though Skeletor will destroy Levitan anyway even if He-Man surrenders.

A spaceship carrying a little girl arrives on Primus. He-Man and the Galactic Guardians are unaware that the little girl is actually a dangerous cyborg used by Skeletor in his plot to bring down the shield surrounding Primus.

The Scientists of Primus create a Super Computer that would link all machines on Primus and the planetary shield. An exiled computer hacker named Mikros collaborates with Skeletor to place a computer virus called the Argazoid into the Super Computer. To combat the Argazoid, the Scientists of Primus use a shrink ray to shrink He-Man, Artilla, Gepple, and Alcon into the computer in order to keep Argazoid from reaching the Vasionic Resonator so that the Evil Mutants can invade.

Using an image projector found on an asteroid, Skeletor disguises himself and the Evil Mutants as Professor Galactica's Interstellar Circus. They use this cover to kidnap the Scientists of Primus in order to have them work on the weapons found on the asteroid.