Synopsis:Skeletor complains to Flogg about the Mutants inability to decode a formula for ‘Energon’, the most deadly substance in the universe. Flogg reckons that the scientists from Primus could decode, Skeletor likes the idea. On Primus, Alcon is extatic about receiving an award for the ‘Mind of the Millenium’, the other scientists point out that they have also received the award, but cannot go and pick it up because Master Sebrian will not let them go. They decide to take Gleep, and ‘borrow’ the Starship Eternia to go and pick up their awards. They arrive at a space station and are greeted by a robot which claims to run it, before picking up their awards they must solve a scientific challenge to prove which of them is most worthy. Gepple suspects something, but is shouted down by the others. While Skeletor and Flogg watch, The scientists attempt to decode the formula, which Gepple notes looks familiar and dangerous. The Scientists eventually decode the formula despite Gepple's warnings, and Skeletor congratulates them using the robot. The Scientists receive their award, all apart from Gepple, as Skeletor notes how happy he is to have ruined someones day. The Scientists return home, and receive a severe scolding from Master Sebrian, as Gepple runs in and informs them that something is wrong with their award statue, which is emitting a bright glow. Suddenly, the statue melts away, and begins to melt away everything in sight. Gepple realizes it is energon, and tells the others that it is used to destroy planets! Adam is watching this on a monitor, and quickly transforms into He-Man. The energon destroys the Scientists' lab, and begins to consume everything in sight, He-Man arrives as the ground beneath the scientists feet begins to give way, leaving them stranded above the melting world around them. He-Man throws his sword across the chasm, and tells the scientists to ride the beam of light it creates across. They escape, and rush to find Sebrian, who reveals that the energon will eventually destroy the entire planet, turning it into a sun. He-Man is about to use his sword to try and stop the energon, but Gepple tells him the only way to reverse its power is to neutralize with a power as evil as energon itself. Sebrian sadly tells the others they must begin to evacuate Primus, and head for outer space. Hydron reports an armada of Mutant ships heading straight for them. The people begin their evacuation, getting onto transport ships. He-Man tells the others he will give himself up to Skeletor in exchange for safe passage for the people of Primus, and conacts him, Skeletor accepts, and tells He-Man to meet him at the centre of the energon’s destruction, stating ‘I want the destruction of this pathetic planet to be the last thing you ever see!’ He-Man, standing in the destruction of the energon, laments his failure to stop the energon, stating he has lost, and Primus is doomed. He-Man tells Skeletor he is not ready to give up without a fight. Skeletor blasts He-Man several times with his staff, finally knocking him off a ledge, Skeletor jumps off the ledge he is on and lunges at He-Man, He-Man creates a crack in the ground with his sword and the two of them fall through it, struggling over the edge. As Skeletor pushes He-Man closer over the abyss, he remembers the words of The Sorceress and Gepple. Energon needs a force as negative as energon itself to stop it, Skeletor jumps into the air, preparing to destroy He-Man, and blasts him again, He-Man holds up his sword and deflects the energy into the energon core below them. As Skeletors energy blast mingles with the energon, the whole area begins to glow, and both He-Man and Skeletor are sent flying upwards as the area begins to become unstable. The energon begins to transform back into the buildings and structures of Primus, as the world begins to return to normal, He-Man triumphantly tells Skeletor ‘Your evil has undone itself!’ Skeletor is furious, He-Man makes to face him, but he summons a shuttlepod and escapes. Back on the Mothership, Flogg tells Skeletor they should have attacked when they had the chance. The Primans have returned to their planet, and celebrate their victory.