Sabrina walks into Ms. Wardwell's home, still unaware that her teacher's person has been taken over by Madam Satan. "Ms. Wardwell" offers her a seat and some cookies but Sabrina wants to get right to the point. Madam Satan lies and tells Sabrina that she's a witch and that she's been watching her from afar for the sake of protecting her. She also admits she used a scrying spell on her mirrors and that that is how she knew that the Batibat was in her house and had her family at it's mercy. Madam Satan lies again and tells Sabrina that it was Edward who asked that she watch over her. Madam Satan claims that she was originally a member of the Church of Shadows, a witch coven in New Hamshire that's also one of Churches of Darkness, until she was excommunicated for falling in love with and getting engaged to a mortal man. After that, she sought out Edward, who made her his student and his secretary when he was the High Priest of the Church of Night. Before he died, Edward asked her to be an invisible omnipresent circle of protection around Sabrina. She goes on to say that she agreed to do it because she fell in love with him. A still upset Sabrina tells Madam Satan to stay away from her and leaves.
Sabrina returns home and reveals to how "Ms. Wardwell" is a witch who used to follow her father. Ambrose tries to convince Sabrina to give "Ms. Wardwell" the benefit of the doubt, but Sabrina can't bring herself to forgive her. However, one thing is for sure, Sabrina's going to clean all the mirrors so that "Ms. Wardwell" can't spy on them anymore.
Harvey is drawing when he sees a vision of Uncle Jesse. He tells Harvey that he is gutless and that his soul is filled with fear. And for it, he will die. This freaks Harvey out but Jesse disappears as Tommy walks in. Tommy then tells him to go to bed before their dad gets mad that he's up still. Roz is up in the middle of the night getting something from the fridge when she sees Jesse. He makes her drop the milk and only disappears when her father shows up. Susie is brushing her teeth when she sees Jesse. He calls her an abomination and “boy-girl.” Frightened, Susie goes to check on her uncle, who is still bound to his bed.
Hilda goes to see Dr. Cerberus about a job .She reveals that she's a very big fan of his as he used to be a horror show host. She's also aware that he used to be Greendale's weatherman. When the demands for horror hosts started to decline, he decided to open on a book store. He then asks Hilda how she feels about costumes before hiring her as a barista.
Zelda listens to the heartbeat of Faustus Blackwood's wife, Constance's baby. She sends Father Blackwood out of the room when he starts asking too many questions. Constance admits that it's a rather trying time for them. She's lost two children before and Blackwood wants a male heir. Zelda hands her a jar to pee in and tells her that they'll know soon enough.
At school, Harvey, Susie, and Roz tell Sabrina about Uncle Jesse. They think he might be possessed by a demon as he hasn't been right ever since he saw something in the Greendale Mines. Sabrina tries to play it off but Roz tells them how she saw Uncle Jesse at her house. Both Harvey and Susie reveal the same thing. Later, Harvey asks Sabrina if she doesn't believe him anymore. Sabrina does believe that he saw something, but he was eight years old when he saw that thing in the mines. Harvey gets upset and leaves because he feels that she isn't telling him the truth. Madam Satan walks up to Sabrina to continue the conversation from last night but Sabrina brushes her off.
Sabrina goes home and tries to get her aunties to help her with Uncle Jesse being possessed. Zelda tells her that they don't mess in mortal affairs and that cases of demonic possession are extremely rare. Sabrina reveals that her friends are talking about demons and that it won't be long before they start talking about witches. Zelda tells Sabrina to make sure friends don't touch Uncle Jesse because then the demon will be able to prey on them too. Unfortunately, Sabrina reveals that they all had to touch him in order to tie him up. Not getting anywhere with her aunts, Sabrina goes upstairs and asks Ambrose for help. He fears that she's getting too cocky, but Sabrina wants to help him by astral projecting in order to at least identify the demon.
Sabrina astral projects to Jesse. He asks her to come closer before realizing that she’s impure. He explains that all he wants is spoiled, debased, and corrupt humans, starting with Jesse. And when he’s done, he’ll move on to a new vessel. The demon inside Jesse explains that Jesse was chosen because he’s sinful, a sodomite to be exact. But more than anything, Jesse was convenient as Jesse set him free. He then reveals that his name is Maerceci. “Overlord of Gluttony. Devourer of Flesh. Demon from the Bowels.” Sabrina tells him to leave, but he refuses and spews vomit acid at her but it goes directly through her as she is merely a protection. Salem, who was watching over Sabrina's body goes to warn Ambrose, who pulls her back into her true form. Ambrose suspects that they're dealing with a higher demon. Some of whom are capable of laying hands on a person's astral body. Sabrina then Ambrose what happened and gives him the demon's name. After a few minutes, Ambrose laughs because his "name" is actually "ice cream" spelled backwards, revealing that the demon lied to her. Ambrose asks Sabrina if there is anything else that she knows about him. She tells him that he said he was set free from the mines by Jesse. This triggers something in her mind as she leaves and goes to see Harvey.
Sabrina apologizes to Harvey about not believing him. She admits that he might've actually seen a monster down there. So she wants to investigate for clues. She asks him to draw her a map to the mines so that she can find some clue as to what is affecting Jesse. Harvey is against it as she would potentially face many dangers. After seeing another vision of Jesse, he decides to go with her. They look through the mines but get separated. After Sabrina finds a clue, a trapping stone, that could lead to the identity of the demon possessing Jesse, she goes to look for Harvey but runs into Madam Satan. Sabrina asks why she's following her. Madam Satan claims that she's just looking out for her, just as she promised her father. The mines are dangerous as the old tunnels lead to Hell. Sabrina tells her again to stay away. Suddenly, she hears Harvey scream and goes running towards him. She finds him huddled in a corner next to a statue of the Dark Lord. He admits that maybe what he saw as a child was just his imagination. The two of them then decide to leave the mines and head home.
Susie's dad, Joe, decides to send Uncle Jesse to a mental institute where he can get the proper help that he needs. He recalls this one time where Jesse was caught wearing their mother’s dress. Their dad caught him and beat him senseless. He always struggled with his sexuality. Susie objects as what happened in the past has no relation to Jesse's illness. Susie demands to see the facility before they send him there.
Roz is at an eye doctors appointment. The doctor tells her that her eye degeneration is steadily progressing. Roz refuses to have the surgery and her dad tries to talk to her about it even though Roz knows that the chances of success are low. Roz asks if God could be punishing her for her lack of faith, much like her nana. She sees a vision of Uncle Jesse.
The next day, Sabrina discovers that the demon's name is Apophis. She wants to fuse the pieces of the trapping stone back together so that they can use it to imprison the demon once more.
Sabrina asks Father Blackwood at the Academy of Unseen Arts if witches can expel demons. The Weird Sisters laugh at her, and Prudence explains that exorcisms are a Catholic right in which male priest call upon the False God for assistance to expel demons. Sabrina reveals that her friend’s uncle is being possessed by a demon, Apophis. What if this brings unwanted attention to the witches of Greendale, she asks. Blackwood replies that it’s not a concern, as possessions involving Apophis rarely last long. Apophis is a parasitic demon, also known as the Devouring Worm. He’s feasting on Jesse from the inside out. If he’s alive, he won’t be for long. After he’s done feasting, he’ll just jump into another host, usually a body that’s already come into contact with Aphophis. Sabrina becomes more concerned about her friends and asks if there is another way to get rid of the demon, to which Blackwood replies that there isn’t for tenacious demons such as Apophis. After class, Nick approaches her and Sabrina reminds him that she has a boyfriend. He asks if she can date two guys since she has two natures. This leaves Sabrina speechless.
Sabrina arrives home to find Madam Satan sitting between Zelda and Hilda. She tells Sabrina she came because she fears she's putting herself in danger. Madam Satan has told them everything from the dangers Sabrina is facing to her being Edward's apprentice. Zelda adds that she wishes she could say she and Hilda were surprised but they knew their brother well enough to know this is exactly something Edward would have done, though she still finds it insulting that her brother wouldn't think they were up to the task of protecting his daughter themselves. Sabrina tells them that she will go to the Catholic Church and ask for help for her friends. Madam Satan offers to help Sabrina with the exorcism by using one of Edward's spells that is a Church of Darkness counterpart to the Catholic exorcism. Hilda decides to go along, leaving Zelda behind. Zelda paces back and forth worried about Sabrina. Ambrose returns with Lady Blackwood's urine sample and tells Zelda to go help them so that Sabrina doesn't get hurt.
Sabrina, Hilda, and Madam Satan stand before Uncle Jesse and recite his real name: Apophis. Devouring Worm. Madam Satan instructs her to speak with a loud and clear voice. The three of them begin the exorcism and call on the witches that came before them: We call forth the witches from the shade. Those who came before us, and died, so that we might live. Visit us, Sisters. Intercede on our behalf. [...] I call forth the powers of Lilith of Aradia, of Morgan le Fay. Visit us, Sisters. Intercede on our behalf. [...] I call on Black Annis, I call on Anne Boleyn. I call on the Witch of Endor. Visit us, Sisters. Intercede on our behalf. I call on Hecate, on Artemis, on Luna to expel this demon. Expel Apophis. Return him to the Dark Lord. Visit us, Sisters. Intercede on our behalf. I call on Hildegard of Bingen, I call Marie Laveau. I call Tituba, I call Mary Bradbury. Visit us, Sisters. Intercede on our behalf. I call Nehman, Badb, Macha. Visit us, Sisters. Intercede on our behalf. [...] I call Circe, I call Moll Dyer. Visit us, Sisters. Intercede on our behalf. [...] I call on Juventas, the virgin, on Juno, the mother-- [...] -Lend us your power. Expel the demon. Visit us, Sisters. Intercede on our behalf. [...] I call upon Cybil Leek. I call upon Priscilla Spellman. I call upon Francis Spellman. I call upon Evanora and Locasta Spellman. [...] Come forth, Kindly Ones. Come forth, Mother of Darkness. Lend us your power. Expel the demon Apophis! Visit us, Sisters. Intercede on our behalf. Visit us, Sisters. Intercede on our behalf. Visit us, Sisters. Intercede on our behalf. Visit us, Sisters. Intercede on our behalf.
Initially, the exorcism doesn't seem to be working until Zelda arrives to help. Uncle Jesse throws up the worm and Madam Satan quickly whisks it away. She throws it down a well along with a sealing stone to keep it there. Zelda tells Sabrina she came for educational purposes. However, she also tells Sabrina she's grounded for disobeying her.
The four of them head home but not before Sabrina thanks Madam Satan for her help. At the Spellman's, Father Blackwood is waiting for them when they return. He threatens to excommunicate them all for having performed an exorcism. Zelda manages to deter him from excommunicating the entire family by revealing test results of the urine sample she took from Constance. They're having twins. Father Blackwood is pleased decides to show them mercy. The next morning, Ambrose's discomfort with house arrest continues to grow. He asked Father Blackwood about possibly being freed but it didn't seem likely to happen. Hilda then receives a call from Mr. Putnam, who reveals that Uncle Jesse died sometime during the night. Sabrina sits with Susie out in front of her house and offers her condolences. Susie tells her that maybe it's better that he died because he would've rotted in the asylum they were going to send him to. Sabrina remarks how she's never seen Susie in a dress before. Susie replies that she's not an abomination and that she will never be one.
Madam Satan comforts Sabrina and tells her that at least she was able to save Uncle Jesse's soul. It may not feel like a victory, but it is as Sabrina brought him peace and made him whole again. In reality, Uncle Jesse only died because Madam Satan had gone back to killed him using a poppet doll. Madam Satan revealed to Jesse that he severed a greater purpose. Sabrina had to perform an exorcism in order to fulfill the prophecy. Sabrina feels like she failed and wonders how she'll ever outwit the Dark Lord. Madam Satan asks what she means.
- This episode is inspired by the 1973 American supernatural horror film The Exorcist.
- In the episode, Luke Chalfant is seen reading a copy of Archie Comics.
- When Zelda calls on the Spellman ancestors, she calls out the names of Evanora and Locasta, which are the names of the Wicked Witch of the East and the Good Witch of the North in the Land of Oz franchise respectively.
- Harvey's Number 10 crop top shirt and headphones are an homage to Johnny Depp's look in the 1984 American slasher film A Nightmare on Elm Street.