Skeletor tricks He-Man into thinking he has accidentally killed a man and, consumed by guilt, He-Man transforms back to Adam and drops his sword down the abyss of Grayskull, deciding he is no longer worthy of Grayskull's powers. Skeletor then opens a portal to the goblin world, enabling General Tataran's army to enter Eternia, with possibly enough power and strength to conquer the planet. Can Eternia survive without its greatest hero... and will Adam realize he has been tricked before it is too late?

He-Man's sword is taken by a peaceful race of Rock People who believe the sword gives them power. Fearing that himself and Battle Cat may never be able to become Adam and Cringer again, He-Man must journey to the underground world of the Rock People to recover the sword.

Prince Adam, Man-At-Arms and Orko are searching the Vine Jungle for the legendary Stone City- but unbeknownst to them, they are being followed by Evil-Lyn, Webstor and Kobra Khan, who are after the city's treasures. By stealing a map, the villains beat the heroes to Stone City, which is filled with realistic-looking statues. When teleporting a life-bringer machine to Snake Mountain, Evil-Lyn accidentally revives the city's warrior king, Vokan! Vokan reveals that his people have been sleeping in stone for thousands of years, to be awakened when Eternia next needs their help. When he notices the life bringer is missing, Evil-Lyn tells him that it is located in Castle Grayskull. Before long, Vokan himself is attacking Grayskull, unwittingly being used by Evil-Lyn, who wants to gain the castle's powers!

Teela and Orko are returning from admiring one of the Eternian farmer's bumper crops, when strong tremors suddenly shake the ground and whole crops disappear. Teela is sucked underground with one of the tremors, where she finds herself in the tunnels of an underground community called the Belats. While Orko raises the alarm, the Belat's King, Subternias, who is determined to feed his people no matter what, holds Teela prisoner, and she finds that the Belats are not evil, but are very mistrusting, after being tricked by Skeletor years before...

The Sorceress sends He-Man, Man-At-Arms, Orko and Battle Cat back in time after Skeletor, who, with Tri-Klops and Fang Man, has gone back into Eternia's past to plant an effective time bomb on the spot where Castle Grayskull now stands, that will destroy it in the present unless He-Man manages to stop it "in time"...

When Beast Man crashlands by Palace Eternia in one of Skeletor's shuttles, Adam, Teela, Man-At-Arms, Man-E-Faces and Ram Man discover that he was being sent to the Dark Moon of Eternia. Curious as to why Skeletor wanted to send him there, they imprison Beast Man in jail and take the ship up there themselves. Reaching Eternia's Bright Moon, they discover that Eternia's two moons are at war with one another after a resident of the Dark Moon reported seeing the people of the Bright Moon causing severe destruction on the Dark Moon. Knowing that the residents of the Bright Moon are innocent, the heroic warriors realise that Skeletor must be the real cause of the destruction, and so Man-E-Faces disguises himself with a Beast Man costume, and goes to the Dark Moon to spy on Skeletor and his warriors and foil their scheme.

Man-At-Arms almost kills the King and Queen when a device accidentally malfunctions, and fearing his skills are weakening with age, considers resigning from his position. Skeletor takes advantage of the situation by installing an energy bug called Byte into the Royal computers to make all the machinery malfunction. Can He-Man find the cause of the problem before it is too late?

Dree Elle comes to Eternia to enlist Orko's help, explaining that an ambitious Trollan wizard called Snoob has defeated Uncle Montork and taken his position as head of the Academy of Magic. Since Montork claims to have felt inexplicably weak when fighting Snoob, they suspect unfair play was used. Orko and Dree Elle go to Trolla, followed by He-Man and Battle Cat, and it soon transpires that Snoob is being controlled by Whiplash, who is trying to learn magic in order to impress Skeletor. It is up to He-Man to stop his scheme, with the help of his Trollan friends!

As Prince Adam and Teela attempt to fix a broken-down Attak Trak in the desert, Orko stumbles upon the wizard Kothos, who was transformed into a sand slug by Evil-Lyn in the earlier episode "The Witch and the Warrior". He turns him back to his true form, but has made a mistake as Kothos captures the heroes and offers them to Skeletor in return for his second-in-command, Evil-Lyn, upon whom Kothos is determined to enact revenge.

Skeletor uses a teleportation device to teleport The Sorceress, in the form of Zoar, to another planet. As He-Man and Battle Cat go to this planet to rescue The Sorceress, Teela is given the task of guarding Grayskull in The Sorceress' place. Unaware that someday she will inherit the position of Sorceress for good, will she be able to live up to her destiny?

When exploring an ancient temple, Prince Adam and He-Man come across the Masks of Power, which conceal the spirits of an ancient evil race. Two power-hungry travellers steal the masks, and their bodies are possessed by the spirits within them. Together they go to Snake Mountain, where they offer Skeletor their services- but Skeletor will only recruit them after they have passed a series of tests, one of which involves recovering the Sword of the Ancients from deep within Snake Mountain.

Once again, Granamyr asks for He-Man's help. The dragons of Eternia are mysteriously disappearing and Webstor and Kobra Khan seem to be behind it.

An inventor called Zicran visits the Royal Palace to deliver a Transmutator machine to Man-At-Arms, accompanied by his daughter Ileena, a friend of Teela's. Ileena is vulnerable and lacking in self-confidence, feeling inferior compared to Teela's agility. Meanwhile, an evil sorcerer called Jarvan, who was previously defeated by He-Man and Man-At-Arms, has escaped from the prison mines and has set his sights on the Transmutator. Preying on Ileena's depression, he disguises himself as a kindly old woman and gives Ileena a 'magic potion' that will boost her confidence and strength. But the potion contains a dangerous drug, and Ileena soon finds herself addicted to the drug, and almost causes several serious accidents while under its effects. She also finds herself unwittingly obeying Jarvan's commands, and helps him to obtain the Transmutator! Can the heroic warriors cure Ileena's addiction before she causes more damage to herself and the people around her?

Negator, an evil character with a love of computers and electronics, sees Man-At-Arms testing out his latest invention, the Beam Ray, in the desert. Impressed, Negator wants the scientist to come and work for him, so that he can use his creations for his own evil purposes. When Man-At-Arms refuses, Negator captures Teela to force him to come to him. As He-Man, Ram Man and Battle Cat search for their missing friends, they are sucked into Negator's underground electronic domain, and Negator sends He-Man and Ram Man into his living electronic "game"...

An irresponsible junior guard, Philip, fails to notice Whiplash sneaking into the palace grounds to steal the King's Ice Raider. He-Man stops Whiplash just in time, but King Randor relocates Philip to the Eternian Weather Station to improve his responsibilities. Skeletor, determined to get hold of the Ice Raider, consults his agent in the North, Icer, and orders him to take over the Weather Station. Icer has no trouble in taking over, and before long weather disasters are occurring all over Eternia.

Skeletor has managed to find the legendary 'Diamond Ray Of Disappearance', a mystical jewel that sends who or whatever it is aimed at vanishing into another dimension. Calling his warriors from around the Universe, Skeletor plans to use the magical gem to get rid of He-Man once-and-for-all. His first victims are King Randor, Queen Marlena, and Man-At-Arms, as well as The Sorceress of Grayskull, and it is up to He-Man to destroy the jewel, freeing his friends from the distant limbo-like dimension that they are trapped in...

For many years, the Royal Palace of Eternia has had shipments of photanium (the strongest metal in the Universe) from the moon of Phantos to make weapons with, but Skeletor intends to from now on step in and have the photanium all for himself. Man-At-Arms is given worthless ore instead of the photanium, and when the moon's ruler, Queen Elmora, puts up a fight against the plans, Skeletor casts a spell on her that ages her and turns her evil. Realising the metal they've been given is useless, He-Man and co. head to Phantos to see what's going on, only to find themselves on the moon where Skeletor now drives slaves mining for the metal...

While entertaining the Royal Family with his magic, Orko finds his act interrupted by a strange sorceress called Majestra. Majestra performs a trick in which she appears to make the King vanish then reappear- but in fact, Majestra is really Evil-Lyn in disguise, and has teleported the King to the dungeon and replaced him with a disguised Beast Man! Evil-Lyn has found a magical Shaping Staff which can transform anything into whatever the holder wishes- and under their disguises, Evil-Lyn and Beast Man set about causing havoc around the palace, turning each member of the Royal Family into helpless animals, while Skeletor awaits them at Grayskull with his latest creation- an evil version of He-Man, called Faker!

Orko runs away, thinking his friends don't really like him. The Sorceress solves his problem, but on his way back to the palace he is captured by Skeletor, who puts him under a spell to reveal the riddle of the jaw bridge. Skeletor uses this riddle to break into Grayskull, and The Sorceress must defend the castle while He-Man tries to free Orko.

An evil dragon called Morning Star hopes to resurrect the age-old war between the dragons and humans on Eternia. He extinguishes the Dragon fire, that powers Granamyr's kingdom, and blames it on the humans. War is declared between the humans and dragons, and He-Man is sent on a mission to recover the dragon fire and put and end to the war.

Angered by his continual defeats, Skeletor blames Beast Man, banishing him from Snake Mountain and his evil forces. Meanwhile, King Randor is preparing for a Royal tour of Eternia, accompanied by Man-At-Arms and a guard of his choice. The King chooses He-Man, but Adam, upset that he always has to play down his qualities to hide his alter-ego, convinces the King to choose him instead. Beast Man spots the touring party, and aided by his Shadow People followers, he ambushes them. Determined to prove his worth to his father, Adam resists transforming into He-Man and instead tries to stop the attack as himself, but he is overpowered, and Beast Man captures Randor, intending to use his capture to win his way back into Skeletor's good books...

An ambassador from another kingdom visits the Royal Palace to present King Randor with a gift. But Man-At-Arms recognises the man as Skeletor in disguise, and in an attempt to stop him, is turned into a crystal statue. He-Man and Teela must journey to the Isles of Darksmoke, where the great and ancient dragon Granamyr knows the only spell to reverse the effect on Man-At-Arms. But their task proves far from easy- for not only is Granamyr suspicious of humans and reluctant to help them, but he says he will only give them the spell if they cut down the living tree named Skytree. Will He-Man willingly take a life if it is the only way to save that of his friend?

Skeletor has gained control of the Cosmic Comet above Eternia, and intends to use it to blow open the jaw bridge of Grayskull. He-Man, Teela, Man-At-Arms, The Sorceress and Orko set out to stop Skeletor's scheme, with the help of Zagraz, a wizard with power over comets.

An evil wizard called Tauron casts a spell on Orko's Uncle Montork and his pet Gark, turns them evil and sets them on Grayskull!

Whilst on an archaeological dig, Man-At-Arms and Professor Smallen are taken captive by ancient robots called Zaktons, who were left by the Ancient Ones to guard the ruins of the desert. He-Man and Teela head to the Ancient Ruins to save them, but they also face danger from Trap Jaw, who wants the Zaktons' artifacts for himself.