The Youngest Hero is the 9th episode of The New Adventures of He-Man.
Flogg calls Skeletor and tells him of his latest plan to attack Primus, which isn’t very original, Skeletor pretends to be impressed, and lets Flogg go on his way, happy to get the Mutants out of the way so he can plan an attack by himself.
On Primus, Caz tells Drissi he’s tired of working with the animals in the Oasis, and wants to join the Primus space force, although Drissi rightly points out he is too young. Caz goes to ask Hydron if he can join the Primus space force, but gets the same reply, just as the Mutants begin their attack.
Back on the Mutant Mothership, Skeletor is performing a spell, which creates a double of him. Pleased with his handiwork, Skeletor then goes on to sing a song about his clone! Skeletor makes the double disappear and spins around to find Quakke staring at him. Quakke is disappointed Flogg left him behind, so Skeletor enlists his help in his own plan, they go to the shuttle bay, where Skeletor unveils a new Shuttle Pod he has designed, which will allow them to pass through the shield undetected.
Flogg leads the Mutants in an attack, as He-Man and the Galactic Guardians arrive to drive them off. The Guardians defeat the Mutants, who then retreat. When the battle is over, Skeletor sneaks past in his special fighter, using its armor to let off a blinding light and slip through the shield.
Meanwhile, Caz steals an unattended Astrosub, and goes off to fight the Mutants to prove himself. He encounters Skeletor and Quakke in their fighter, and opens fire, but his blast has no effect. Skeletor's ship blinds Caz, and then extends two claws which grab the Astrosub. Skeletor and Quakke return to Nordor with Caz as their prisoner, Skeletor then infects Caz with a virus using his staff, saying it will keep him subdued.
Skeletor contacts Master Sebrian and tells him and Adam that Caz has come down with a fever, and that he will bring him to them if they call off their guards at the shield. Sebrian agrees, and they go to meet Skeletor in the Oasis.
He-Man, Sebrian and Drissi go to meet Skeletor in the Oasis. Skeletor and Quakke arrive in their ship and hand over Caz, but He-Man suspects something when Skeletor simply leaves after handing him over. The Scientists attempt to cure Caz of his virus, but find that nothing is working. He-Man realizes what Skeletor is trying to do, and contacts him, Skeletor tells He-Man he will release Caz from the virus if He-Man gives him his Power Sword. He-Man is forced to agree, with no other options.
He-Man and the others go to meet Skeletor again, this time taking Grot with them. He-Man refuses to give Skeletor the sword until he cures Caz, Skeletor agrees to He-Man's terms and returns Caz to normal. He-Man then hands over his sword to a thrilled Skeletor, who tells Quakke to take it back to the ship.
With his sword gone, Skeletor decides to attack He-Man, and Grot attacks Quakke before he makes it back to the ship with the sword. Skeletor reveals his double from earlier to a shocked He-Man, who is forced to dodge the blasts coming from both Skeletors. Quakke lunges at Grot with his mega mace, but hits a number of large rocks, which fall down and interrupt the fight between He-Man and Skeletor. Both Skeletors drop their staff, as He-Man stands atop a rock holding a huge boulder above his head. He-Man throws the boulder at one of the Skeletors and the other disappears.
Grot gets He-Man's sword back from Quakke, and returns it to its owner as Skeletor and Quakke retreat, with Skeletor crying out ‘Just once I’d like to win!’. He-Man tells Caz he knew which Skeletor was which because the real Skeletor squinted when the suns were in his eyes, telling Caz ‘Its now always the strongest who wins Caz, knowledge can be as powerful as a sword.’ He-Man tells Caz to study and be ready to join the Primus space force, and the episode ends.
After Caz crashes Grot's harvesting cart, Grot advises not to use any machine unless you know how does it work.
- This episode includes the first proper space battle in the series.