After experiencing traumatic nightmares of a time now past, the Sorceress summons Prince Adam and Cringer to Castle Grayskull to give Adam a precious, jeweled sword and send the pair to the planet Etheria to investigate its secrets. Unsure of what they are expected to find, the Prince and his companion befriend the Great Rebellion, a small group of citizens fighting a huge intergalactic army, known as the Evil Horde, ruled by the vicious tyrant Hordak. During a titanic battle, Adam transforms into He-Man to help the rebels, but is soon captured by the Horde’s Force Captain, Adora, and placed under Horde surveillance.