DC Comics; DC Database; IMDb; Rotten Tomatoes; Superman Wiki; TV Tropes; Wikipedia
This came out in 1984, the year after "Superman III." I'm actually not that familiar with the Superman movie franchise, but I think this is supposed to be a canonical spin-off, even though Superman doesn't appear in it. Anyway, I'm not sure exactly when I first saw this movie, but it must have been on TV sometime in the late 80s. I think. It definitely wasn't successful either critically or financially, but I kind of liked it. I mean, I recognized it as being... not good... but it had a certain campy charm. And it didn't hurt that Supergirl (Helen Slater) and her nemesis, Selena (Faye Dunaway), were both quite easy on the eyes. Anyway, I got the movie on DVD in 2015, and watched it again on the day an unrelated Supergirl TV series premiered.
The movie begins in a city in space, Argo City, which had been founded by a Kryptonian artist named Zaltar (Peter O'Toole). He had some kind of crystal wand thing that he used to create sculptures and stuff. And he had "borrowed" one of the city's power sources, a sphere called the Omegahedron, which I guess supercharged the wand. He's talking with Kara Zor-El (the cousin of Kal-El, aka Clark Kent, aka Superman). Zaltar gives Kara the wand to play with, and she goes off on her own while he's talking to her mother, Alura (Mia Farrow). He then surreptitiously kicks the Omegahedron in Kara's direction, presumably so Alura wouldn't see him with it. She powers up the wand and brings the dragonfly-like thing she'd drawn with the wand to life. And it flies off and breaches the paper-thin wall protecting the city from, you know, space. The Omegahedron gets sucked out, and Zaltar plans to go after it in a capsule, but Kara sneaks onto the capsule before he can, and chases it herself. Meanwhile, Zaltar realizes he'll have to be sent to the Phantom Zone as punishment for causing the city to lose its power source. (Incidentally, it was said the city could only survive a few days without it, but it's clearly a lot more than a few days before Kara returns to Argo City at the end of the movie.)
Meanwhile, on Earth, Selena is having a picnic with a man named Nigel. She dabbles in the dark arts, but apparently Nigel knows a lot more about it than her (yet for some reason, he's a math teacher at a boarding school). Selena wants to take over the world, but Nigel says she's too impatient. Then the Omegahedron falls out of the sky, Selena picks it up, and somehow instinctively knows it's super powerful. So she no longer has any need of Nigel, and dumps him. She goes back to the spooky amusement park funhouse where she lives with her snarky sidekick, Bianca, and begins making plans. Of course, she doesn't exactly know how to use the Omegahedron, but it doesn't take long for her to start powering up her magic with it. But soon after she obtained it, Kara arrived on Earth, and already had a costume much like the one worn by Superman (except, you know, with a short skirt instead of tights). Apparently she can change her clothes (and her hair color) just by thinking about it. (Which might have made sense if she still had the wand with her, which she didn't. Then again, she did have a bracelet that had been made by the wand... which is what she'll use to track the Omegahedron. Except most of the time she can't, because Selena was storing it in a sort of demonic-looking sculpture-box thing made of lead, which blocks the signal, I guess.) Meanwhile, Kara infiltrates a boarding school as a student, calling herself Linda Lee. By an amazing coincidence, it's the very school where Nigel works, but even more amazingly, she becomes roommates with Lucy Lane, the sister of Lois Lane. (Lucy is played by Maureen Teefy, whom I know from Grease 2.) Oh, and Lucy is dating Jimmy Olsen, who actually is played by the same actor as in the Superman movies.
Um... anyway... when Kara first got to Earth, she immediately started using her new powers, including super strength, heat vision, and flight. And then she landed in the middle of a street at night, and was accosted by a couple of truckers who pretty clearly planned on raping her. (One of them was played by Matt Frewer.) Of course she kicked their asses. Elsewhere, on another day, there was a hunky landscaper named Ethan, who caught the eye of Bianca. But Selena decided she wanted him for herself, so she got him to come to her place, pretending to want some landscaping work done. But instead, she gave him a potion that would make him fall in love with the first person he sees after drinking it. It knocks him unconscious, and meanwhile, Selena and Bianca get distracted, and he wakes up and wanders off in a stupor. It's pretty amazing that he managed not to see anyone, because he was stumbling around quite awhile with lots of people yelling at him to get out of the street. But whatever. Selena uses her newly enhanced power to scry for him with her mirror, and... sort of vaguely casts a spell to bring him back to her, and... she clearly didn't know exactly how the spell would work, nor am I going to spoil it. Because it's ridiculous. But it did tons of damage and put lots of people in danger, so... Kara (or rather "Linda") went to save Ethan, and ended up being the first person he saw. So he fell in love with her, which somehow turned him into a poet. (And he stole a kiss from her, which I'd think should have earned him the same reaction as the would-be rapists got, but that's not how movies work. I also feel the need to mention I'm not sure how old Kara was supposed to be- I think the actress was around 20, but the character was quite possibly underage, but of course that's a non-issue in the movie, so I could be wrong.) Anyway, when Selena watches all this, she starts referring to Kara-in-the-super-costume as "Supergirl," a name that I guess everyone else will eventually start using, too. Though oddly, she doesn't realize Linda is Supergirl. Oh, and I also want to mention that the spell eventually wears off, but Ethan still loves Linda... which is absolutely preposterous, because they still don't know each other, like, at all.
Anyway, there will be various battles between Supergirl and Selena, which are mostly pretty ridiculous, until eventually Supergirl defeats her (after it seemed as if Selena had defeated Supergirl). And... Kara takes the Omegahedron back to Argo City. The end.
So... yeah. Like I said, it can be kind of a fun movie if you're in the mood for something campy. I do wish it would have been better written (like much better written), but... it was okay. And I did like Slater's portrayal of Kara, for the most part. She had a sort of endearing sweetness and naivete, but could also be brave and tough, when necessary. I felt like in a well-written film (or film series), she could have been pretty great. So it's a shame she was stuck with this hot mess.