Beast Island is a first season episode of the animated television series She-Ra Princess of Power, produced in 1985. Written by Larry DiTillio, directed by Gwen Wetzler.
At the rebel camp, Madame Razz and the Twiggets use their magical powers to find He-Man; he is being held captive on Beast Island. Razz eventually manages to conjure up a flying ship and the rebels fly to Beast Island in an attempt to rescue their newest ally.
On the island itself, Force Captain Adora confronts the imprisoned He-Man, telling him that the sword he dropped feels as if it were made for her. He-Man agrees, but adds that the sword is only for one who is on the side of good. Adora says that she serves the rightful rulers of Etheria, but He-Man suggests she go out into the world and see what the Horde is really like.
Hordak and Shadow Weaver discover the rebel ship on their own way to Beast Island, and Hordak promptly shoots it down. Glimmer's powers manage to save the rebels from serious injury, but she is left very weak by the exertion. Hordak and Shadow Weaver find themselves suspicious of Adora's wishes to leave the safety of the Horde, but allow her to leave. The rebels come face to face with one of the monsters that inhabit the island; they flee from the monster, unable to stop it. Just when they are almost cornered, Battle Cat launches some fruit at the monster, blinding it and forcing it to leave.
At the prison stronghold, Adora and her steed Spirit leave the island in an attempt to prove He-Man's accusations wrong. As she leaves, the rebels successfully manage to break into the Fright Zone, only to have Grizzlor face off against them. Adora travels the world and begins to witness some of the Horde's atrocities against innocent people.
The rebels fend off a battalion of Horde Troopers and soon find themselves in the room where He-Man has been chained. Just as they prepare to free him, Hordak and Shadow Weaver overpower them, Shadow Weaver paralyzing them with gas. Hordak plans to exact punishment on the rebels if He-Man does not tell him why he has come to Etheria. The Horde leave to let him consider this offer, and then Kowl appears, having escaped the paralyzing gas, and immediately sets about freeing He-Man. He-Man releases the imprisoned rebels, but the alarm is set off and the entire Horde are alerted to their escape attempt. He-Man uses his great strength to take care of the Horde Troopers that stand before them; arriving on the launch pad of Beast Island He-Man battles Grizzlor's Destructo-Tanks as the rebels prepare to steal a Horde ship to make their escape.
Adora returns to the Fright Zone, confronting Hordak and Shadow Weaver about what she has now seen with her own eyes. Shadow Weaver determines that the sword Adora carries is somehow weakening the spell cast on her; she puts Adora to sleep with her magic and retrieves the sword, vowing to Hordak that she will learn the secrets of the sword, along with He-Man's secrets as well.