10 Scariest Sci-Fi Movie Endings Ever

While a research team is exploring in Antarctica, they discover there is an shapeshifting alien among them. When this entity assimilates a form, it can perfectly replicate its appearance, voice, mannerisms, and memories, making it almost impossible to tell which of the explorers are who they say they are. What's worse is the group estimate this creature could consume all life on Earth within a matter of years if it reaches a heavily populated area.

Unsurprisingly, the group can no longer trust one other and begin attacking and even killing each other, assuming one of them is the Thing. After the creature has absorbed or killed nearly everyone in the team, MacReady and Childs seemingly kill the Thing by blowing up the entire research station.

But because Childs and MacReady were separated while the station exploded, they have their suspicions that the other is the alien. Unable to trust one another, the pair stare at each other until they both freeze to death. For 40 years, this climax has haunted viewers as they still debate which of the characters, if either, is the Thing.