Adventure starring HeIen Slater. On a desperate mission to save Planet Earth, SupergirI (Slater), must retrieve a missing life-giving power source to save her home city from totaI destruction. StartIed by her own amazing Superpowers, Supergirl traces the lost Omegahedron only to discover that it has faIlen into the hands of the rapacious SeIena (Faye Dunaway) who unleashes untold horrors to thwart her young adversary.