Terrorists hijack a 747 inbound to Washington D.C., demanding the release of their imprisoned leader. Intelligence expert David Grant (Kurt Russell) suspects another reason and he is soon the reluctant member of a special assault team that is assigned to intercept the plane and hijackers.
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.