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 King Randor's beautiful but snobbish and stuck-up niece Lady Edwina comes to stay at the Palace, Orko is attracted to her and tries unsuccessfully to impress her. He thinks back to a magical medallion that he once had when he arrived on Eternia years before in a freak storm, when he saved a young Prince Adam and Cringer from the Tar Swamp, losing the medallion in the process. He heads off to the swamps to try and find the lost charm to impress Edwina, but unfortunately he is there at exactly the same time as Skeletor, who, with Evil Lyn and Beast Man, has come up with a magical potion to resurrect ancient beasts from the swamp to use in an attack on the Royal Palace...

Adam, Teela, Orko, Cringer and Lizard Man are on a visit to Pangus, the King of the city of Tarinth, when the city comes under a fierce trembling. Adam is about to come to the rescue as He-Man when a young woman called Celice appears and soothes the tremors with her singing. Pangus explains that a terrible creature lives beneath the city, and only Celice's soothing singing can calm it.

Skeletor oversees the whole scene and decides that Celice's singing powers would be of great use to him. Evil-Lyn kidnaps the girl with Trap Jaw, and possesses her; Skeletor plans to use her siren song to hypnotise The Sorceress and then to sing Castle Grayskull's jaw-bridge open...

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...

Orko's magic pyramid inadvertently saves Dree Elle, a female Trollan (Orko's species), who was hiding from Dragoon, an evil fire-breathing half man, half dragon who is terrorising Orko's home word of Trolla. On hearing the threat to his world, where he is a great magician, Orko promptly returns with Dree Elle in the pyramid. Knowing that their friend will need some help, He-Man and Battle Cat get The Sorceress to open a portal to send them to Trolla to help their friend, and find themselves in Orko's bizarre, back-to-front world, where they must put an end to Dragoon's reign of terror before sundown, or the portal back to Eternia will close...

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?

He-Man and Battle Cat rescue a young girl in the jungle from three soldiers, and she tells them she is Princess Raya of the kingdom of Abherran, and the soliders were minions of Queen Valena of Targa, Ahberran's rival kingdom. He-Man journeys back to Ahberran with Raya, hoping to somehow stop the war between the two cities, but on the way He-Man is knocked unconscious by a falling tree and taken prisoner by Valena's soldiers.

When he awakes he has lost his memory and has been imprisoned with an arena fighter called Garn, whom Queen Valena has promised freedom if he wins his next fight. He-Man is forced to fight Garn, but his main aim is to regain his memory and free the countless slaves whom Valena is forcing to fight for amusement. And will he regain his memory in time to help Raya return safely to Ahberran, and stop the war?

A villain called Azrog is arrested on Trolla by Uncle Montork, but he flees to Eternia where he joins forces with the witch Spydra. Montork follows him, but ends up imprisoned in Spydra's castle. When He-Man, Battle Cat, Teela and Orko go to rescue Montork, Orko falls under Azrog's spell and becomes evil, and is set against his friends.

When on a skiing holiday in the icy regions of Eternia, the Royal Family are captured by an Ice Lord. Orko scares the Ice Lord by pretending he is He-Man (!), and the Ice Lord explains that Skeletor has kidnapped his daughter and will only release her if the Ice Lord delivers the Royal Family to him. Orko convinces the Ice Lord to free Prince Adam (who he calls his 'assistant'), then Adam becomes He-Man and sets off to Snake Mountain with Orko to rescue the Ice Lord's daughter.

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.

Queen Sybilline, apparently once one of the most evil sorceresses in Eternia, has defected to the side of good. She enlists the help of He-Man and his companions in restoring King Danton of the Isle of Tears to the throne, having helped the evil Gorgon to overthrow him. But will they succeed, when Gorgon has recruited Evil-Lyn as his replacement sorceress?

Clawful and Trap Jaw have stolen ‘the Horn Of Evil' from Trolla and returned with it to Eternia, so Dree Elle, with her mischievous younger brother Yuckers, heads to Eternia to warn Orko and his friends of the imminent danger. The evil duo intend to use the horn's black magic on Castle Grayskull, but thats just half of the trouble in store, as Yucker's love of practical jokes not only causes irritation for Orko and Dree Elle, but also puts them in great danger...

Adam and Teela visit an ancient castle where an evil Lord and Lady once lived, practising black magic by absorbing energy from the trees, until the trees died and they began a centuries-long sleep in their coffins. As Adam and Teela ride some winged horses, Lady Valtera and Lord Tyran awake from their coffins. Lord Tyran's appearance has been greatly disfigured by his evil ways- so severely that Valtera does not recognise him. When Valtera comes across Adam and captures him to be her slave, Tyran thinks she is more interested in Adam than him and wreaks havoc attempting to gain all the power he can, and capturing Teela along the way.

Now that the House of Shokoti has been risen from the Sands, and Lord Masque has been defeated, the heroes retire to bed for the night, planning to investigate the temple in the morning. But Stanlin, whom Melaktha has refused permission to join the expedition, is determined to see inside the temple for himself, and forces Ram Man (who has been put on night guard) to ram down the temple's door for him. Ram Man gives in to his wishes, but is knocked unconscious by the force of the blow, and Stanlin soon finds himself a helpless prisoner of Shokoti herself.....