When a scientific experiment goes awry, the residents of St. Louis face a deadly nightmare as a massive black hole and an intergalactic creature swirl through the city, devouring everything in their paths. In a race against time, scientist Eric Bryce (Judd Nelson) and his assistant (Kristy Swanson) work frantically to close the rip in the sky and conquer the beast before the Pentagon can carry out its plan to nuke the black hole.