A group of scientists try to track down and trap a killer alien seductress before she successfully mates with a human. In 1993, the Search for Extra Terrestrial Intelligence Project receives a transmission detailing an alien DNA structure, along with instructions on how to splice it with human DNA. The result is Sil, a sensual but deadly creature who can change from a beautiful woman to an armour-plated killing machine in the blink of an eye. Government agent Xavier Fitch assembles a team of scientists and mercenaries to locate and destroy Sil before she manages to find a mate and breed.