Post Description

The film is about a group of scientists who try to track down and trap a killer alien succubus before she successfully mates with a human male.

The alien is the result of the SETI (Search for Extra Terrestrial Intelligence) program. Earth's scientists sent out transmissions with information about Earth and its inhabitants, DNA structure etc, in hopes of finding life beyond Earth. They then receive transmissions from an alien source on how to create endless fuel effortlessly. Therefore, the scientists assume that this is a friendly alien species. But from a second alien transmission, the scientists receive information about an alien DNA along with instructions on how to splice it with human DNA. A government team led by Xavier Fitch (Kingsley) goes forward with the genetic experiment hoping to induce a female with "docile" traits. One of the hundred experimental ova produces a girl named Sil, who looks like a normal human but develops into a 12-year old in 3 months.

Sil's rapid development makes the scientists consider her a threat. They try to kill her using toxic gas but instead she breaks out of her containment cell and escapes out into the world. The government assembles a team composed of anthropologist Dr. Stephen Arden (Molina), molecular biologist Dr. Laura Baker (Helgenberger), empath Dan Smithson (Whitaker) and assassin/tracker Press Lennox (Madsen) to track and destroy Sil.

Sil matures rapidly into an adult (Henstridge) in her early twenties with supermodel good looks. This makes tracking her extremely difficult. She is incredibly strong and intelligent with amazing regenerative powers. For instance, after an accident, she is knocked unconscious and breaks her scapula, but to a doctor's amazement, it heals before his eyes. The scientists fear she may mate with human males and produce offspring that could eliminate the human race. Sil does not have any inhibitions when it comes to killing people who get in her way and wants to produce offspring as soon as possible. She frequently morphs into her alien form—a bipedal creature with tentacles on her shoulders and back.

Sil tries first to mate with a man she meets at a night club, but rejects and kills him after sensing that he is diabetic. She then tries to mate with a man she meets after a car accident; this is interrupted by Press and Laura. She kills the man and flees into a forest without being seen by the team.

She then takes an attraction to Press and attempts to seduce him (no one able to recognise her because she cut her hair and dyed it brown) but sees that he's in love with Laura. She eventually copulates with Arden who doesn't recognise her as well; then kills him when he realises who she is and what he has done. The tracking team then follow her into the sewers where Fitch is killed and a cave where she and her offspring are destroyed. The last scene shows a rat chewing on one of Sil's severed tentacles; it starts to mutate into a vicious beast and attacks another rat.

The creature was created and designed by Swiss artist H. R. Giger, who also created the creatures in the Alien films.