Beyond the Door (1974 film)

Beyond the Door (Italian: Chi sei?, lit. 'Who are you?', also released as The Devil Within Her) is a 1974 Italian supernatural horror film directed by Ovidio G. Assonitis and Roberto D'Ettore Piazzoli, starring Juliet Mills, Gabriele Lavia, and Richard Johnson. The plot follows a San Francisco housewife (Mills) who becomes demonically possessed in the midst of a pregnancy.

Beyond the Door opened in the United States in May 1975, and became a major commercial success, grossing approximately $15 million. Critical reaction to the film was largely negative, with numerous critics deeming it an imitation of The Exorcist (1973). That film's distributor, Warner Bros., filed a lawsuit against the production company behind Beyond the Door, claiming copyright infringement. A settlement was ultimately reached in 1979.

This would be the first entry into the Beyond the Door trilogy in the United States as Mario Bava's Shock (1977) was re-titled Beyond the Door II and branded as a sequel, though it has no relation to the 1974 film other than the presence of actor David Colin Jr.. A second sequel, Beyond the Door III, was also released in 1989, though it too bears no relation to the previous two films.