Members of an American scientific research outpost in Antarctica find themselves battling a parasitic alien organism capable of perfectly imitating its victims. They soon discover that this task will be harder than they thought, as they don't know which members of the team have already been assimilated and their paranoia threatens to tear them apart.
When an alien takes the form of a young widow's husband and asks her to drive him from Wisconsin to Arizona, the government tries to stop them.
Nada, a wanderer without meaning in his life, discovers a pair of sunglasses capable of showing the world the way it truly is. As he walks the streets of Los Angeles, Nada notices that both the media and the government are comprised of subliminal messages meant to keep the population subdued, and that most of the social elite are skull-faced aliens bent on world domination. With this shocking discovery, Nada fights to free humanity from the mind-controlling aliens.