Madam Satan sits by the fire as she tells a mysterious someone about the night of the storm. She goes on to say that all the signs were there: a dead bird brought in by a cat, the spilled bottle of black ink, a broken mirror in an empty room, a loaf of bread split cleanly down the middle, and a blind woman knitting her own death shroud aware of what's coming.
Roz tells her Nana Ruth that she was right about the Cunning and that she has started seeing things. She recounts what she saw and how she suspects that Sabrina is a witch. She asks her grandmother if it was a Spellman who cursed them with blindness. Nana Ruth informs her that it wasn't a Spellman and that Roz knows in her heart if Sabrina is good or bad. Roz says that she isn't sure anymore. Nana Ruth instructs her to just look at Sabrina and she'll know. Nana Ruth goes on to say that Sabrina isn't the witch she needs to fear because the thirteen witches are coming.
At the Spellman Mortuary, Sabrina refuses to go to school because she's worried that she'll see Harvey. Zelda gives her a balm that Hilda made to ease her heart. She instructs Sabrina to rub it on her chest, three times daily. But Sabrina doesn't want to stop feeling. She simply wants to stop hurting. She also wants Harvey to stop hurting and asks Zelda what she's supposed to do. Zelda tells her to go about her normal routine and that tomorrow she'll do it again and again until it hurts a little less. Sabrina isn't sure she can and asks Zelda for further advice, but Zelda has never been in her position.
Sabrina goes to school but spots Harvey and heads to the ladies' room. There, she runs into Roz and Susie. They ask her what's wrong after having called her all weekend. She tells them she wasn't feeling well. Susie comes right out and asks if she's a witch. Sabrina denies it but Roz tells her that the Cunning showed her a vision. Sabrina finally admits to being a witch and breaks down. She tells them everything about the Academy of Unseen Arts and Tommy. They hug her and she apologizes for lying to them.
Madam Satan continues to talk to the hidden figure. She tells them that she came up with a plan for a threat to come to Greendale in order to force Sabrina to make certain choices.
At the academy, Nick sends his condolences to Sabrina after her failed resurrection. He asks her how things are going with Harvey. Sabrina reveals that he's devastated and that they've broken up. Nick can't believe she really loves Harvey. That's the one thing he envies about mortals. They can give themselves to each other. He says witches are bad at love because Satan wants them to love him alone. He'd trade all the witch-orgies in the world for what Sabrina and Harvey had. Suddenly, the statue of the Dark Lord that they're standing in front of starts to bleed.
Out in the woods, Madam Satan sacrifices a jock to summon the Greendale Thirteen at midnight, the witching hour. The Greendale Thirteen rise, and she informs them that they're in Greendale. The witching hour is upon them. For that night and the following, from midnight to one, they could walk the earth again to claim their revenge. Lastly, she tells them to summon "the butcher," who will end Greendale once and for all.
Dr. Cerberus and Hilda clean up the shop as they near closing time. The lights start to flicker, and Hilda feels a chill. She compares it to a train going past a graveyard. Unbeknownst to her, the Greendale Thirteen are near. Faustus Blackwood senses them as well while working in the Desecrated Church. He demands that they show themselves. Instead, they set his book on fire.
Dorothea awakens Susie from her sleep. Susie goes to her window and sees the thirteen witches. Dorothea informs Susie that the Greendale Thirteen have returned to land of the living. They were hung to death many years ago by witch hunters, and Dorothea buried them on the farm after cutting them down from the trees as they had been abandoned by their own kind. The Greendale Thirteen are wrathful and have come for vengeance. Susie asks how they can stop them but Dorothea has disappeared.
Ambrose and Luke are in the woods when they stumble upon a witches circle. They're performing a summoning spell. Suddenly, they disappear. Ambrose goes to investigate and finds a figurine among the ashes of their fire pit. As he turns to leave he gets grabbed by a witch who tells him to take back a warning to the Church of Night.
Sabrina speaks to Harvey in the library. She finds out that he lied to his father and said that Tommy shot himself to put himself out of his misery. He adds how they called a different funeral home in Riverdal. Sabrina tells him that she's been thinking about him nonstop and that she's wanted to call him so badly. Since learning that Sabrina is a witch, there's so much he understands about her now. She surmises that he must hate her. Harvey replies that he could never hate her, but every time he looks at her ,he thinks of Tommy. Suddenly, Hilda appears and tells Sabrina that they have to go to the Church of Night straight away. Father Blackwood has called an emergency meeting. Harvey tells her to go and Sabrina does, but she tells him that she hopes they can talk some more later.
At the Desecrated Church, Father Blackwood claims that the Dark Lord is angry with them for their disregard of witch-law but then Ambrose and Luke storm into the church and reveal that the Greendale Thirteen have returned. Last night, they rose to call forth their Crimson Avenger. Tomorrow night, during the witching hour, they will release their Red Angel of Death and it will go forth and kill every firstborn in Greendale. Father Blackwood tells them not to worry and that they'll just hide at the academy since it's magically protected. Sabrina worries about the mortals but Father Blackwood tells her to let them go to their false god to safety. He reminds everyone that they have to be at the academy at midnight or else.
Sabrina asks Zelda and Hilda why the Greendale Thirteen would be angry at them. Zelda tells her that it's because the coven had decided to sacrifice them in order to appease the humans and their bloodlust. Essentially, they were scapegoats to quell the rising witch hysteria. The coven could've come together to save the Thirteen, but their ancestors decided not to help them. Sabrina refuses to abandon her friends. Zelda agrees that they should all stay and protect the town. Ambrose asks how they're going to protect everyone. Zelda suggests gathering them all in one place. Hilda tells them that Dr. Cerberus told her that the town is to gather at Baxter High during severe weather or tornados. The four of them gather around a table and summon the different winds to them to create a tornado. Zelda calls on Boreas, North Wind. Hilda calls on Euros, East Wind. Ambrose calls on Notos, South Wind. And Sabrina calls on Zephuros, West Wind. Before long, the warning sirens begin to sound off. Zelda prays that the mortals will heed the warning.
Most of the mortals of Greendale gather at Baxter High. Principal Hathorne shares with Madam Satan how he's always been fascinated with tornados ever since seeing the Wizard of Oz. He suggests that the two of them get a drink after the storm passes.
The Church of Night seeks shelter at the academy as planned. All except the Spellmans. Blackwood had hopes for Ambrose but remarks that he made his choice.
Sabrina can't find Harvey at the school and Susie can't find Roz. They leave to find their friends. Sabrina goes to Harvey's but he tells her that he isn't leaving his dad or the house. Sabrina reveals that what's coming isn't a tornado. It's an attack formed by witches. However, Harvey doesn't want to rely on the protection of Sabrina or any witches.
Susie finds Roz with Nana Ruth, who doesn't want to leave her home, forcing Roz to stay as well because she doesn't want to leave her grandmother behind. They reveal to Susie that what's coming isn't a storm, rather the Greendale Thirteen and their Crimson Avenger. Susie begs Roz to leave, but when she refuses, Susie decides to stay with her.
Sabrina arrives back at the school, where she reunites with her family. She tells them that she had to go to Harvey and then stop to call in a favor.
Nick arrives at Harvey's and tells him that he's Sabrina's friend and that he's going to help protect him for the night. Harvey asks the warlock what kind of friend he is exactly.
The witching hour is upon them and the Greendale Thirteen begin their attack. The witches at the academy begin to chant protection spells as does Nick, who's protecting Harvey despite the fact that he's a witch hunter. Meanwhile, Susie watches over Roz, while she watches over Nana Ruth. Suddenly, Roz sees a figure walk past the window. One of the Thirteen forces Ruth's door open. Susie takes the lead and explains that she is Dorothea's descendant, who gave them passage across the ocean when no one else would and who cut them down after they were hanged. Susie states that the Walkers are her friends, and the witch leaves.
The Spellmans perform a protection spell over the school Sabrina asks if the spell is working. Zelda says that it is and will continue to so long as the four of them stay focused. She is then summoned to the academy by Father Blackwood. Zelda is angry for having been taken away from her family but Blackwood tells her that Constance Blackwood is in labor. Zelda says that she'll need clean towels, fresh water, and Prudence.
Sabrina questions if the three of them will be able to hold the protection over the school. Hilda believes so assuming as no one else disappears. Just then Ambrose is summoned to the academy by Luke. Ambrose is visibly upset and asks him what has he done. Luke says that he brought him to the academy because he loves him.
Madam Satan tells Sabrina and Hilda that they aren't going to be able to hold out much longer. Fortunately, she has a plan. Sabrina rushes off with Madam Satan, leaving Hilda alone with Salem to protect the school. Madam Satan takes Sabrina back to where her Dark Baptism almost took place. She tells Sabrina that she must sign her name into the Book of the Beast because it's the only way she'll be strong enough to save Greendale. Madam Satan insists this is the only way she'll be able to save her family and friends. Sabrina finally relents and says that she'll sign as she hears the Red Angel of Death arriving in Greendale on his horse. Madam Satan disappears and the Dark Lord appears behind Sabrina. He asks if she is signing his Book of her own free will and tells her that she must answer his call, whenever, wherever. He slashes her palm and squeezes one drop of blood onto the book below. Sabrina thinks back on everything that's happened as she signs her name in the Book. Sabrina has Dark Baptized herself and becomes a full-fledged witch. Madam Satan reappears and tells her that the Dark Lord has already shown her what to do. Sabrina thinks back to the vision she saw of the hanging witches and how the tree they hung from was on fire.
Lady Blackwood continues to go through labor. One of the babes is pushed out but something is apparently wrong as Zelda doesn't show the baby to Lady Blackwood, who then tells Prudence and Zelda that her children must be preserved no matter what.
Dr. Cerberus finds Hilda and tells her that she should be downstairs. Hilda claims that she's saying a prayer and Cerberus clasps her hands hoping to help.
Roz questions how Susie managed to convince the attacking witch to leave. Ruth tells them that she left because it's now the Crimson Rider's turn. She can hear as he approaches on his horse.
Nick and Harvey barricade the front door as the Crimson Avenger attacks. Nick asks Harvey if he's the firstborn, which he isn't. Nick asks about his dad, who unlike Harvey, is a firstborn son.
The Crimson Avenger attacks Baxter High. Hilda tries to keep it out of the school. She asks Cerberus if he's a firstborn. He reveals that he's the oldest of three boys, so Hilda performs a spell and tells him to run away: Hear me, heed me. Run away. Live to see another day.
Madam Satan and Sabrina into the clearing, near the tree where the Greendale Thirteen were hanged. Sabrina summons the witches to her. They question who is Sabrina to summon them and state that they refuse to be hanged again. Sabrina informs them that she intends to burn them. The Greendale Thirteen don't appear concerned as only the most powerful of witches can summon Hellfire. Sabrina then calls forth fire from the pits and burns the Greendale Thirteen. As she does, her hair changes from blonde to white. Because the witches who summoned him had been were gone, and the wrath that fueled him dissipated, the Angel of Death, vanished as well, as though he was never there.
Harvey and Nick open the door to the house, relieved to see that Sabrina had managed to save Greendale. Harvey asks Nick why he came tonight. He asks if they're seeing each other. Nick tells Harvey that Sabrina loves him. That she'd die for him and maybe that's enough to forgive her.
Father Blackwood enters the office to find that Lady Blackwood is dead. Zelda tells him that he only has one son because the baby had consumed his brother in the womb. Blackwood replies "As it should be." He holds the child and names him his heir.
Roz kisses her grandmother on the forehead before she covers her with a blanket. She'd died during the storm. Roz watches as her spirit exits the room.
After the storm has passed, Dr. Cerberus walks Hilda home. He tells her it's going to be a beautiful day and they kiss. As he walks away, his eyes glow yellow, suggesting that he's not mortal after all. Upstairs, Zelda reveals to Hilda that she took Lady Blackwood's firstborn child who is a girl. She feared what Blackwood would do if he found out about the child. Zelda believes that they can keep the child a secret and raise her together, she and Hilda. However, Hilda informs Zelda that she's moving out of their bedroom.
Sabrina visits Harvey in his bedroom. He thanks her for sending Nick to protect him and his dad. Sabrina has come to apologizes again. She's truly sorry. He's willing to start over with no secrets between them, but Sabrina doesn't know if its safe for him or Roz or Susie now that she's signed her name into the Book of the Beast. Harvey asks for one last kiss. Sabrina stands up and kisses him before she disappears.
Madam Satan concludes her story. The hidden figure she's been talking to is Principle Hawthorne, who she has tied up in the chair across from her. He asks her who she is. She reveals that she is Lilith, or Madam Satan as she likes to be called. But soon she'll have a new title. She'll be known as Queen of Hell after grooming Sabrina to take her place as Satan's foot soldier. She peels off her face and reveals the demonic features beneath. She then eats Principal Hawthorne. Afterward, her familiar, Stolas, points out that it seems the Dark Lord is grooming Sabrina to stand by his side rather than Madam Satan. However, she doesn't believe that the Dark Lord would betray her and says that there's a very simple solution for that as she snaps her familiar's neck.
Back at school, Harvey, Susie, and Roz sit in the library and wonder if they're still friends with Sabrina. Harvey remarks that there's something different about her. Only partially referring to her hair. They're unsure where this leaves their friendship. Meanwhile, at the Academy of Unseen Arts, Sabrina struts into the school dressed like the Weird Sisters. She winks at Nick as she passes by.
- The Witching Hour is a time of night (usually midnight) associated with supernatural events.
- Nick calls Harvey "Farm Boy". In the 90's sitcom, Sabrina the Teenage Witch, a character named Roland would call Harvey that name as a way to insult him.
- The tie-in novel Daugher of Chaos reveals that December 10 is the date the episode is set in.