This is the story about a group of scientists who try to track down and trap a killer alien from n 1974, when the United States government relayed a message containing information about Earth and its inhabitants--including the DNA sequences that make up the human cell--to the rest of the galaxy. But now twenty years later, a reply finally arrives, containing a unique sequence of DNA--along with the friendly instruction to combine it with their own. A top secret experiment is undertaken and within weeks one of the injected human ova grows into a seemingly normal female child, called "Sil." It soon becomes apparent, however, that she possesses dangerous alien characteristics. "She" is part human, part alien, beautiful, strong, very dangerous and desperate to mate with a human being.

During the production, MGM opted not to shoot the "nightmare train" sequence to keep costs down. H.R. Giger was not willing to accept that, however, so he spent $100,000 of his own money to finance the sequence.

Xavier Fitch:
We decided to make it female so it would be more docile and controllable.


Preston Lennox:
More docile and controllable, eh? You guys don't get out much.

Boom mic visible: Visible in the reflection off the glass patio door when Robbie brings Sil back to his house.

Written by James Labirt and Larry Labirt
Kevin Oliphant and Daryl D. Bonneau
Performed by Daryl D. Bonneau