Summary
Highlights
The movie opens with a nun named Marie attempting to escape a convent in the dead of night. She steals keys from Mother Superior, but is caught by four hooded nuns who break her leg and trap her in a coffin.
American nun Cecilia arrives in Italy to join a remote convent, picked up by Deacon. She is greeted by Mother Superior and assigned to Isabelle, who reveals the convent is built on catacombs and serves as a hospice. Cecilia meets Gwen, another nun, who makes unsettling comments about Father Tedeschi.
A ceremony welcomes Cecilia, where she takes her vows and meets Father Tedeschi and Cardinal Merola. Tedeschi, a former scientist, tells his story. Cecilia shares her near-death experience at 12, believing God saved her for a reason she's yet to discover.
Cecilia witnesses a nun crying with a red cloth over her face and then collapses after being given an old nail from the crucifixion. Later, she's disturbed by a figure and a sick elderly nun who cuts her hair, revealing branded crosses on her feet. Cecilia becomes violently ill, and after examinations, she is shocked to discover she is pregnant, despite being a virgin. The convent declares it a miracle.
Cecilia is honored, but Gwen is skeptical. Gwen attempts to drown Cecilia, screaming that 'it was supposed to be her', before nuns apprehend her. Isabelle then jumps from a building, her face mangled. Gwen expresses her concern to Cecilia about the strange events and the lack of proper medical care for Cecilia, leading to her being silenced by Tedeschi and Deacon.
Cecilia finds a Bible verse warning about Satan behind a fallen painting. She then discovers a file containing personal information about her near-drowning. She witnesses Gwen being brutally punished and an old woman giving her a cross, claiming 'she will never leave.' Cecilia fakess being sick to escape to a hospital, but Mother Superior discovers her ruse. Tedeschi then reveals their true intentions: years of experiments to impregnate nuns to resurrect Jesus using DNA found on a relic, with Cecilia being the successful vessel. They brand her feet with crosses, a mark she saw on the old woman, proving the longevity of these sadistic experiments.
In her third trimester, Cecilia learns from Cardinal Merola that the child could be the Savior or the Antichrist. She attacks Mother Superior and Cardinal Merola, killing them. She sets fire to Tedeschi's lab, but he puts it out. Cecilia escapes into the catacombs, where she finds Gwen's mangled body. Tedeschi pursues her, but Cecilia kills him with the holy nail. She escapes into the woods and gives birth to a grotesque, non-human baby. She then takes a rock, implying she will kill the creature.