This essay examines the themes of paranoia and claustrophobia as elements of horror in John Campbell’s novella “Who Goes There?” (1938) and John Carpenter’s film-adaptation of said novella, called The Thing (1982). The novella and the film utilize the lack of trust and reliability in between the characters as elements of fear as well as supernatural elements in the form of a monster. This essay focuses on the different parts of the story running through both versions, mainly the setting, the characters and the monster, to show how the themes of paranoia and claustrophobia are used throughout these as elements of fear and horror. With the help of Sigmund Freud’s concept of the uncanny, as well as other sources, this essay argues that while the monster plays an important role throughout the story, the threats created by the paranoia and claustrophobia are equal to the monster itself.