A US research station, Antarctica, early-winter 1982. The base is suddenly buzzed and attacked by a helicopter from the nearby Norwegian research station. They appeared to be trying to kill one of the dogs from the US base. Having dealt with the threat, the members of the US team fly to the Norwegian base, only to discover them all dead or missing. They do find the remains of a strange creature the Norwegians burned. The Americans take it to their base and deduce that it an alien life form. After a while it is apparent that the alien can take over and assimilate into other life forms, including humans, and can spread like a virus.