A big-budget spin-off from the series of three successful Superman movies, this film stars Helen Slater as the counterpart to the famous comic-book superhero. Supergirl is Kara, Superman's young cousin. She is sent to Earth is search of a Krypton power source, a lost ring that has been turned into a paperweight. She disguises herself as Linda Lee, a meek high-school student. Peter O'Toole is Zaltar, a mad villain who wants to use the power of the ring to take over the world. Faye Dunaway plays the evil sorceress Selena, who is also plotting to get the gem and uses her incredible powers of black magic in service of her scheme. Linda Lee meets Ethan (Hart Bochner), who is under a spell cast by Selena, which causes him to fall in love with the first person he sees. Selena had intended to use the spell to make Ethan fall in love with her, and she is furious when his affections are directed toward Supergirl.
by Michael Betzold synopsis