Beyond the Door Italian title Chi sei? is a 1974 ItalianAmerican horror film codirected by Ovidio G. Assonitis credited as Oliver Hellman and Robert Barrett. The film stars Juliet Mills and Richard Johnson, and was released in the UK in a reedited format as Devil Within Her.
Dimitri, a lover from her past, shows up claiming to be able to help her, but it turns out he is in league with the entity possessing her, and is aiding the birth of her child, assumed to be the Antichrist, in exchange for the thing saving him from dying in a car crash years before. The film ends with the entity turning on Dimitri, and suggesting all events were done for its own amusement. The entity then kills Dimitri, leaves Jessicas body, and the child is stillborn. At the end of the movie the young boy is seen throwing a toy red car a symbol of toying with Dimitri in the bay suggesting that he is the Antichrist.The interior shots were filmed on set in Italy at the Incir De Paolis Studios in Rome, while all exteriors were shot on location in San Francisco. Film Ventures International acquired the film for distribution in the United States for 100,000. ........
Source: Wikipedia