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.

Frank Leone is nearing the end of his prison term for a relatively minor crime. Just before he is paroled, however, Warden Drumgoole takes charge. Drumgoole was assigned to a hell-hole prison after his administration was publicly humiliated by Leone, and has now arrived on the scene to ensure that Leone never sees the light of day.