Original Airdate: ?/?/1985
As Adora and Kowl await the opening of a dimensional gate and a visit from Adam, Horde Troopers are patrolling the edge of the Whispering Woods. Adora transforms into She-Ra to eliminate the threat. Kowl tricks them into getting stuck in a hollow log, and She-Ra is able to toss the log into a nearby swamp.
Adam arrives to greet his sister, while back on Eternia, Modulok is demonstrating the potential of his Dimensional Gate-Maker to Skeletor, evil lord of destruction. Skeletor plans to use it to send the royal family to Etheria, hoping that they will become Hordak's problem, thus enabling him to rule of Eternia without any resistance. He sees great potential in being able to transport whole Eternian cities to Etheria.
Modulok feels as though his talents are being wasted in serving Skeletor, and so he opts to take his Gate-Maker to Etheria and work for Hordak, where those talents will be more appreciated. Seeing his schemes of grandeur endangered, Skeletor follows him through the dimensional gate. Adam and Adora observe the villains emerge from the gate, and simultaneously call upon the power of Grayskull to become He-Man and She-Ra. They approach Skeletor, who reveals that Modulok has invented a Dimensional Gate-Maker and plans to present it to Hordak.
Skeletor agrees to a brief truce with He-Man and She-Ra while they plan to get the Gate-Maker back. After a brief encounter with an Etherian delicacy called Spoo, Skeletor ends his truce with the twins of power and escapes the Whispering Woods, meaning that She-Ra and He-Man now have the combined threat of Modulok, Hordak, and Skeletor. At the Fright Zone, Modulok presents himself and his Gate-Maker to Hordak, and seeing the value that the device could have in conquering whole planets, Hordak accepts his offer to join the Horde.
The first planet that Hordak plans to conquer is Eternia, which will enable him to further the spread of the Horde across the universe while likewise taking revenge on Skeletor. Skeletor arrives at the Fright Zone and briefly skirmishes with Hordak, asserting that Eternia is his planet to conquer. A short while later at the edge of the Whispering Woods Hordak prepares his invasion of Eternia, his squadron of Horde ships already maneuvered into position above the planets surface, waiting for the gate, which will take them to Eternia.
He-Man and She-Ra arrive to confront the Horde, destroying Horde tanks and Horde Troopers as Skeletor looks on. He refuses to help them, instead holding back to see who wins the battle, so that he might challenge the victor. Shadow Weaver uses a spell to create a magical electrical creature, utilizing the energy of the Dimensional Gate-Maker. This places a strain on the Gate-Maker, and He-Man and She-Ra use that to their advantage, by letting it capture them and then crossing swords. The reversed polarity short-circuits the Gate-Maker, as the Horde ships pass through the gate to a now unpredictable location.
Modulok cannot make another Gate-Maker, as the first one was made out of very rare minerals. This prompts Hordak to demote Modulok from Horde scientist to Horde cook. He-Man and Battle Cat call upon the Sorceress to open a dimensional gate, so that they may return to Eternia, their mission accomplished. At first, Skeletor balks at using He-Man's gate to escape, not wanting to take help from a hero, but when a group of Horde Troopers menace him, he speeds through the gate back to Eternia. The invading squadron of Horde Troopers on an alien world, with odd-looking creatures, conclude that they are not on Eternia.
Synopsis by Michael Cravens