An archeology professor and his students embark upon a digging expedition in Nevada. But when his favorite pupil learns that he has been planting artifacts to boost his academic fortunes and vows to report him, he diverts their schedule to explore an old mining shaft in the foothills, hoping to use the distraction to persuade her to reconsider.
Emerging from the opposite end of a tunnel, they find a derelict airbase, seemingly abandoned since World War 2. The group branches out to investigate the site and are attacked by merciless creatures up to fifty feet in height, forcing the survivors to run for shelter within the hillside caverns where a mysterious stranger awaits them. The star student finds herself caught in a desperate struggle between her former mentor’s determination to protect his interests and the colossal monsters of nuclear nightmare.