A DoD special agent is sent to investigate the failure of a space-shuttle just above earth. What seems to have killed the astronauts is a creature specially designed on Earth to perform terra-forming on Mars. Of course, as you already suspects, the creature doesn't just create vegetation in order to produce oxygen, it also has some nasty homicidal tendencies. Actually, it feeds on humans. So our special agent goes to meet the scientists who've created the monster to figure out a way to kill it. Again we don't have a full-on military strike, just one law-enforcement agent and a couple of scientists hunting what seems more dangerous than the T-Rex. Yeah, right. The creature settles in a small town in Illinois, where everyone is dropping dead from cancer, which is caused by their uranium-contaminated water purification system (the main water pump is in an old uranium mine, and nobody suspects anything in this town, although they had 38 deaths in 7 years, and over two thirds of the population suffering some form of cancer... another priceless thing in this movie). We also have a "traitor" in the team (it's an inside job, as they say). And yada yada, so on and so on. It's boring as hell, and you could really live better without watching this.
What makes this movie worth watching is Theresa Russell. She does her acting job as usual. But this time, she looks really sexy. I'm telling you, it doesn't matter that she's old. She is a real MILF. And she will certainly lead you through the movie, without switching it off.