A young couple named Zach and Samantha McCall have recently gotten married and went to the Dominican Republic for their honeymoon. They visit a fortune teller who keeps repeating to Sam, "they've been waiting for you". Afterwards, the couple finds themselves lost on an unknown street they do not remember seeing. Wanting to return to their hotel, they get offered a lift from a pushy cab driver who offers to take them to a local bar. The couple reluctantly accepts. The couple begin partying and both soon pass out drunk. They are both then seemingly taken to an underground chamber in the nightclub where Sam is subject to some kind of ritual by an unseen force. The next morning, Zach and Sam wake in their hotel with no memory of the previous night.
A couple weeks after the honeymoon, Sam discovers she's pregnant despite claiming to have taken birth control pills "religiously" ever since the wedding. Though shocked, Zach and Samantha are overjoyed and tell their family and friends the news. The couple later attend their first ultrasound scan where the doctor says that the baby looks healthy and Sam is due by the end of March. At that moment, the ultrasound screen goes static but recovers after a moment. Throughout the course of her pregnancy, Sam begins to experience nosebleeds, stomach bruising, cravings for raw meat despite being a vegetarian, super-strength and telekinetic abilities and unexplained feelings of rage whenever she or the baby appear to be threatened. Also, Zach and Sam keep seeing odd-looking people randomly watching their house. Sam becomes convinced something is seriously wrong with the baby. After a second visit to the doctor, a new doctor appears. When it becomes evident that Sam is uncomfortable with having the child, someone (presumably the cult, including the new doctor) places tiny hidden cameras in the McCall's home to monitor her progress and make sure she doesn't hurt the baby.
When Sam is eight months pregnant, the couple attend a holy communion at their church. The priest who officiated Zach and Sam's wedding looks at Sam during the service and begins to violently cough up blood. Later at home, when Zach is reviewing the communion footage he filmed, he sees the mysterious cab driver more often than he should as well as a strange symbol. He visits the Priest in hospital, who explains the symbol is related to summoning the Antichrist. Zach decides to investigate the symbol further and breaks in to an apparently abandoned house at the end of his street where he finds the CCTV footage of his house inside and is almost caught by the house's inhabitants who appear to be performing a ritual. Zach barely manages to escape.
Upon returning home, Zach hears Sam scream and all the glass in the house smashes. 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 own blood with her stomach cut. She cries and wonders if the baby is alright before dying. Zach breaks down in grief before the cab driver and the second doctor appear. Zach begs the intruders to leave them alone, but the doctor takes the baby regardless. Zach is then arrested and is being interrogated by the police on the death of his wife and disappearance of his child. His fate is left unknown. The ending shows another young couple, on their honeymoon in Paris, where the same cab driver offers a lift.(En Wikipedia)
