Rosemary's Baby is a 1968 American horror/thriller film.
The story focuses on Rosemary Woodhouse, a bright but somewhat naïve young housewife, and her struggling actor husband Guy after they move into the Bramford, a New York City apartment building with a history of unsavory tenants and mysterious events. Their neighbors are an elderly and slightly absurd couple, Minnie and Roman Castevet, who tend to be meddlesome but seem harmless. Guy becomes unusually close to the pair while Rosemary tries to maintain a distance from them. Guy lands a role in a play when the actor originally cast suddenly and inexplicably goes blind. Soon afterwards he suggests that he and Rosemary have the child they had planned. On the night they plan to try to conceive, Minnie brings them individual ramekins of chocolate mousse, but Rosemary finds hers has a chalky undertaste and surreptitiously throws it away after a few tastes. Shortly afterwards she has a dizzy spell and passes out. She experiences a strange dream in which she is raped by a demonic presence.
A few weeks later, Rosemary learns she is pregnant. She plans to be treated by Dr. Hill, recommended by her friend Elise, but the Castevets insist she see their good friend, famed obstetrician Dr. Sapirstein. For the first three months of her pregnancy, Rosemary suffers severe abdominal pains, loses weight, and craves raw meat and chicken liver. The doctor insists the pain will subside soon and assures her she has nothing to worry about.
When her old friend Hutch sees Rosemary's wan appearance, he is disturbed enough to do some research, and he plans to share his findings with her but falls into a coma before they can meet. He subsequently dies but before he does instructs his friend Grace Cardiff to deliver the book about witchcraft on his desk to Rosemary. Photographs, passages in the text he marked, and the cryptic message "the name is an anagram" lead the young mother-to-be to realize Roman Castevet is really Steven Marcato, the son of a former resident of the Bramford who was accused of worshiping Satan. She suspects her neighbors are part of a cult with sinister designs for her baby, and Guy is cooperating with them in exchange for their help in advancing his career.
An increasingly disturbed Rosemary shares her fears and suspicions with Dr. Hill, who, assuming she's suffering from a hormonal imbalance, calls Dr. Sapirstein and Guy. The two men bring her home, where she goes into labor. When she awakens following the delivery of her baby she's told he died shortly after birth. However, when she hears an infant's cries somewhere in the building, she suspects he still is alive. In the hall closet she discovers a secret door leading into the Castevet apartment, where the coven meets, and finds the congregation gathered, worshiping her newborn son, the spawn of Satan. Rosemary considers killing the demon infant but, after some coaxing from Roman, she begins to hum a lullaby to the boy. The film ends leaving the audience to draw their own conclusions about the future of Rosemary's baby.