 Sil 's violent outbursts during sleep make the scientists consider her a threat . They try to kill her using <unk> gas but she breaks out of her containment cell and escapes . The government <unk> a team composed of anthropologist Dr. Stephen Arden ( Alfred Molina ) , molecular biologist Dr. Laura Baker ( Marg Helgenberger ) , " <unk> " Dan <unk> ( Forest Whitaker ) and mercenary Preston " Press " Lennox ( Michael Madsen ) to track and destroy Sil . Sil matures rapidly into an adult ( Natasha Henstridge ) in her early twenties and makes her way to Los Angeles . Her body strength , <unk> ability and intelligence make tracking her extremely difficult . The scientists fear she may mate with human males and produce offspring that could eliminate the human race . Sil is intent on producing offspring as soon as possible , and kills several people to prevent them from notifying the authorities or simply to use their clothing . 
