A research team at a remote research station in Antarctica finds an alien being that has fallen from the sky and has remained buried in the snow for over 100,000 years. Unfrozen and unleashed, it creates havoc and terror as it changes forms and becomes one of them.

In the midst of a snowfield in Antarctica, the scientists and workers of a small American research base are shocked when a helicopter begins to circle their camp, chasing and shooting at a dog. The helicopter is destroyed and the passenger's aboard are killed. The dog is let into the base. The helicopter is Norweign made and probably linked with the base that is close by. J.R. MacReady travels to the Norweigan base and finds the place destroyed. He...