| Director | Matt Bettinelli-Olpin, Tyler Gillett |
|---|---|
| Budget | $7 million |
| Box office | $36.9 million |
Zach McCall and his fiancé, Sam, decide to begin a video diary the night before their wedding so that their future child will have a record of their family history. After their wedding, they travel to the Dominican Republic for their honeymoon. After attending Carnival, they stop to speak to a palm reader who tells Sam she was "born from death" and that "they have been waiting for her." Sam and Zach become frightened and leave.
They find themselves lost on an unfamiliar street and unable to return to their hotel. They eventually find a taxi driver, who offers to take them to a nightclub. They reluctantly accept his offer and, after taking various shots in the club, fall unconscious. Sam is seemingly brought to an underground chamber, where she is subjected to a satanic ritual and engulfed by an unseen force.
Zach and Sam awaken in their hotel the following day, unaware of the previous night. A couple of weeks after the honeymoon, Sam discovers she is pregnant despite claiming to have taken birth control pills "religiously" ever since the wedding. Though shocked, Zach and Samantha are overjoyed and share the news with their family and friends.
The couple later attends their first ultrasound scan, during which the doctor says that the baby looks healthy and that Sam is due by the end of March. At that moment, the ultrasound screen goes static but recovers after a moment.
Throughout her pregnancy, Sam begins to experience a series of abnormal symptoms: nosebleeds, stomach bruising, cravings for raw meat (despite being a vegetarian), superhuman strength, telekinetic abilities, and violent acts of rage whenever she or the baby appears to be threatened. Also, Zach and Sam keep seeing strange people watching their house from afar. Sam becomes convinced that something is seriously wrong with the baby and that they are being watched.
After a second visit to the doctor, a new doctor appears and performs an amniocentesis after Sam appears nauseous. He has no answer as to the whereabouts of their original doctor. Zach reveals Sam's parents were killed in a car accident when she was in utero, and she was removed via caesarean. Before the couple returns home, masked men set up hidden cameras to monitor her progress and make sure she does not hurt the baby.
When Sam is 8 months pregnant, the couple attends Holy Communion at their church. Their usually friendly niece is oddly scared of Sam, and the priest who officiated Zach and Sam's wedding looks at Sam during the service and violently coughs up blood.
Later, at home, Zach reviews the communion footage he filmed and sees the mysterious cab driver sitting in a pew. He also reviews the footage from their night at the club and notices strange symbols on the doors. He visits the priest in the hospital, who explains that the symbol is related to summoning the Antichrist.
Separate footage reveals three friends walking in the woods, where they find slaughtered deer. They suddenly discover Sam eating a deer's intestines. When they try to speak to her, Sam kills them telekinetically.
Zach investigates the symbol further and asks his sister, Suzie, to stay with Sam. He breaks into an apparently abandoned house at the end of his street, where he finds the CCTV footage of his house and the missing ultrasound. He is almost caught by the house's inhabitants, who appear to be performing a ritual. Zach barely manages to escape.
When he does, he sees their second doctor, the man who was watching their house, the cult leader, and the cab driver who picked him up among the worshipers performing the ritual.
Upon returning home, Zach finds the house surrounded by the masked men who have been watching them all along. Inside, he finds Suzie dead and hears Sam scream as the house is being destroyed by the beast within Sam, fighting to get out.
He finds Sam in the baby's nursery, standing in a trance-like state with a knife to her stomach. Zach screams for her to stop, but she presses the knife to her stomach anyway, and there is a violent blast of light.
When Zach recovers, he finds Sam lying in her blood with her stomach cut. She cries and wonders if the baby is all right before dying. Zach grieves before the cab driver and the second doctor appear.
Zach begs the intruders to leave them alone, but the doctor takes the baby. He is then arrested and interrogated by the police on the death of his wife and sister and the disappearance of his child.
The ending shows another young couple on their honeymoon in Paris, where the same cab driver offers a lift, implying that the cycle will start again.