The Conjuring Universe had two spin-off prequels featuring the creepy doll Annabelle, but the other thing that has become significant in the series is the demonic nun, first seen in The Conjuring 2, so this spin-off focuses on her. Basically, set in 1952, in Romania, at the Saint Cartha's monastery, two nuns entering a tunnel to retrieve an ancient Christian relic are attacked by an unseen evil force. The surviving nun, Sister Victoria (Charlotte Hope), flees from the attacker, a demon appearing as a nun, and hangs herself. Her body is discovered by Maurice "Frenchie" Theriault (Jonas Bloquet), a villager who transports supplies to the nuns. The Vatican learns of the incident and summons Father Burke (Demián Bichir) to Rome. They ask him to travel with Sister Irene (Taissa Farmiga, Vera's sister), a novice nun, to investigate the situation. While Sister Irene is teaching children the relationship between religion and science in a school, when she is interrupted to accompany Father Burke to Romania. There they meet with Frenchie, who leads them to the abbey. They discover Victoria's body and take a key from her corpse. Then they encounter Mother Abbess (Gabrielle Downey) who informs them that the nuns observe a period of silence during the night and offers them a place to stay at the convent. Frenchie is returning to the village when he is attacked by a demon, but he escapes. Burke tells Irene about a boy named Daniel (August Maturo) he exorcised in the past; he is haunted by the memory of the boy's death who was fatally injured. Irene reveals that as a girl, she had visions causing the Church to take an interest in her. That night, Burke is rescued by Irene after being buried alive in the graveyard by the demonic entity. The next day, Irene and Burke return to the abbey, but only Irene can enter. She meets some of the other nuns and learns that they are praying constantly, swapping in shifts, to keep the evil entity at bay. Sister Oana (Ingrid Bisu) tells the story of the abbey's history. It was built in the Middle Ages as a castle by a Duke (Mark Steger) obsessed with the occult. The duke summoned the demon through a rift in the catacombs but was killed by Christian knights, who sealed the rift with a vial filled with the Blood of Christ. However, the bombings during World War II accidentally reopened the rift, unleashing the evil entity once again. Burke identifies the demon as Valak (Bonnie Aarons) and discovers the Abbess has been dead all along. Frenchie heads back to the abbey to help Irene and Burke. Irene is attacked by Valak and joins the nuns in desperate prayer to ward off the demon. But Irene discovers that none of the nuns she had seen and talked to were real, and that Victoria had been the last nun in the abbey and had sacrificed herself to stop Valak from possessing her body and unleashing evil. They theorise that Valak can only be stopped if they seal the rift with the blood of Christ contained in the reliquary. Irene then informs Burke that God has called her to make her solemn vows as a nun and asks Burke to elevate her to the status of a professed nun. After the trio unlocks the tunnel door with the key Victoria possessed, Irene is lured into a pentagram and possessed by Valak. Frenchie smears some of the blood of Christ on her face, casting out the demon. Burke is wounded by Daniel's ghost as Valak starts to drown Irene in a flooded chamber. Irene expels the blood of Christ in the demon's face, banishing it as the blood of Christ seals the rift. After Frenchie resuscitates Irene, he reveals his real name. Unbeknownst to the others, Maurice has been possessed by Valak, indicated by an inverted cross on his neck. Twenty years later at a university seminar, in Wakefield, Massachusetts, Carolyn Perron (Lili Taylor) watches Ed (Patrick Wilson) and Lorraine Warren (Vera Farmiga) and the footage of their attempt to exorcise a possessed Maurice. Also starring Sandra Teles as Sister Ruth, Manuela Ciucur as Sister Christine, Ani Sava as Sister Jessica, Maria Obretin as Sister Abigail, Michael Smiley as Bishop Pasquale, and Joseph Bishara as the voice of the Demon. Bichir and Farmiga are fine, there was only a little bit of a story I could follow, the many appearances of the evil nun are certainly memorable, the jump scares don't always work, but the special effects are good, and the eerie atmosphere is reasonable, a slow but not terrible gothic supernatural horror. Worth watching!