There Is an Alien Here

In the year 2020, a small number of Alien Research Club members gather in underground bunkers, having survived the invasion of yellow liquid aliens. Chaos ensues when an alien that had infiltrated somebody gets into the body of one of the members. There is a moment of desperation when they realized everyone will die if they don't find and kill the alien within 30 minutes. Who is the alien hiding in? Can the last humans be safe in the face of the alien invasion?