Supergirl is a spin-off of the Superman film series and follows Kara Zor-El, the cousin of Superman, as she travels to Earth to recover a powerful Kryptonian artifact and become a hero in her own right. Kara Zor-El (played by Helen Slater) lives in Argo City, a Kryptonian colony that survived the destruction of Krypton and now exists in a separate dimension called Inner Space. When the Omegahedron, a powerful energy source, is accidentally lost and ends up on Earth, Kara follows it to retrieve it—knowing its loss could doom her people. On Earth, the Omegahedron is found by Selena (Faye Dunaway), a power-hungry witch who uses its dark energy to try to rule the world. Kara adopts the identity of Supergirl, hiding as “Linda Lee,” a student at an all-girls school while she searches for the artifact. Supergirl faces challenges fitting in on Earth, controlling her powers, and battling Selena’s dark magic. Along the way, she befriends humans and begins to understand the value of compassion and courage.