|“||They are the next eldritch terror, bearing down upon us, causing these tremors, promising our extinction. They are horrors from the stars, the Cosmic...||”|
Metatron, an angel in the celestial realm speaks of the gathering Eldritch Terrors. They say that the witches, mortals, and infernals will be allowed an opportunity to restore order themselves. If they fail, Metatron will negate Sabrina.
Sabrina and Roz host a Q & A at Baxter High during their run for student council President. One student in particular, Milo, represents the Astronomy Club, which is in need of funding. Their telescope broke last semester and despite numerous requests, they haven’t gotten any funds to repair or replace it. Roz offers to see what she can do to raise their budget. In the meantime, Sabrina will ask her cousin to fix the telescope. Nick then suddenly appears in a Baxter High variety jacket.
Ambrose implores Blackwood to reveal the identity of the next Eldritch Terror, but he refuses to tell Ambrose anything of use. So, Prudence decides to pry the information from him via her psychic abilities, but he has locked the contents of his mind away in a safe.
Baby Adam is crying uncontrollably with Lilith having very little means to provide comfort. Hilda interrupts and asks Lilith if she has a plan moving forward with her life. Lilith intends to remain hidden in the room until Adam’s 16th birthday. He’ll come of age and challenge and defeat Lucifer to claim the throne, thus making Lilith 'Queen Mother.'
Nick explains to Sabrina that he just transferred to Baxter High in order to get closer to her. However, Sabrina isn’t over their breakup or the fact that he hurt her. Nick recently realized that one the reasons he could never fully commit to her was because he never spent any time in her world. She spent her time between Baxter High and the Academy, so he’s doing the same. Not only is Nick an official student at Baxter High, he’s also the captain of the wrestling team and a member of the LGBTQ Alliance. Billy passes by and greets Nick, welcoming him to the wrestling team. Sabrina informs Nick that she needs time, to which he replies that he’s willing to wait for however long it takes. An earthquake seemingly shakes the school. They exit the library to find that stalagmites have pierced through the floors of Baxter High.
While monitoring the realms from the Observatory, Mambo Marie notices the stalagmites that have popped up across the world.
Sabrina Morningstar and Lucifer have come to learn that Hell is not flowing as well as it should upon their return from the tour of the Nine Circles. Beelzebub questions what she means by this. Sabrina points to the overcrowding of Hell. Caliban suggests annexing the mortal realm into a tenth circle. Instead, Sabrina instates a new rule: one soul in, one soul out. For every new sinner, they release one of the souls they already have. Lucifer then asks where Lilith is. Before Beelzebub can respond, Billy and Lizzie have somehow teleported to Hell and look to Sabrina for answers. Sabrina wipes their memories and sends them back.
Hilda brings Lizzie and Billy their milkshakes but their booth is completely gone. When she turns back around, it has reappeared with Billy and Lizzie as if they never left.
Sabrina asks Ambrose to repair the Astronomy Club’s telescope, but he’s more concerned about the Eldritch Terrors, which Sabrina doesn’t seem to be as concerned with. He in fact admires her ability to compartmentalize. Sabrina then tells Ambrose about Nick attending Baxter High and the subsequent earthquake, which Ambrose had no knowledge of.
Theo awakens to the sound of giggling in his room. He screams in fear after being startled by Moth, Robin’s hobgoblin friends. Theo demands answers. Before Robin can explain, Moth blows a face full of white dust into Theo’s face, rendering him unconscious as Robin and Moth exit through the window.
Sabrina heads down into the mortuary where a statue from Hell has arisen from the ground beneath. Ambrose wonders the cause, though he doesn’t think it’s an Eldritch Terror necessarily.
Greendale’s town sign has appeared in Hell, much to the surprise of the Morningstars, Caliban, and Beelzebub, who claims its a declaration of war, as the witches have turned to Hecate.
Prudence teleports to Roz, as she needs her help for a special mission in relation to the Eldritch Terrors. She and Roz teleport to the Pilgrims of the Night Church, where Blackwood’s corpse has begun to rot and is infested with maggots. They find Judith and Judas bowing down at their father’s feet, almost as if they were worshipping him.
Harvey calls Sabrina and tells her that a "goat demon rock" has appeared inside his home. Sabrina reports this to Ambrose, who rushes outside at the sound of another earthquake. Another statue from Hell has appeared. This time in their front yard. Ambrose is then called to the Academy by Mambo Marie.
Sabrina and Ambrose meet Mambo Marie in the Observatory to discover that the mortal realm and the infernal realm are pushing together. Ambrose reveals that this is the result of two Sabrinas existing simultaneously. Now the two realms are falling into each other to crush one or both Sabrinas. Sabrina admits that Ambrose is right and agrees to tell the aunties.
Sabrina enters Aunt Zelda’s office to find her and Hilda speaking to Sabrina Morningstar, Lucifer, and Caliban. Zelda asks who else knew. Sabrina reluctantly reveals that Ambrose was aware of the existence of Sabrina Morningstar, and then Zelda calls him into her office to scold him.
At Cerberus Books, Robin reveals to Theo that Moth is one of his old friends from before he fell in with the pagans. Robin explains that hobgoblins, along with fay folk, and fairy folk, feel things that others can’t. According to Moth, the Eldritch Terrors are coming, and so all the hobgoblins are leaving the mortal realm for the fay realm permanently, and they want Robin to join them. Robin is considering leaving, but he wants Theo to come with him.
Nick finds Sabrina Morningstar, Lucifer, and Caliban in the lobby. He asks to speak with Sabrina privately. Under the impression that she’s Sabrina Spellman, he tells her that he will leave her alone if she says that there’s no hope for them, but if there’s even a 1% chance that she might forgive him, then he’s willing to wait. Sabrina reveals that she’s Morningstar, not Spellman. However, she does believe that Spellman will take him back.
Prudence and Roz demand that Blackwood tell them everything he knows about the Eldritch Terrors, but still he refuses to tell them anything. So, they decide to torture the answers from him. Prudence has over a dozen sharp needle pins and sticks them into his corpse, a pain so excruciating that Blackwood can still feel despite his head being removed from his body. Disgusted by the act, Roz leaves for school.
The Spellmans and the Morningstars sit down to discuss the impending collision of Hell and Earth. Ambrose explains that chaos begets chaos. A chain reaction has begun that won’t stop until the two realms crush each other. Lucifer suggests killing one of the Sabrinas. Ambrose isn’t sure that would fix the problem. They need to do more than stop the collision. The need to push the two worlds away from each other. Having eavesdropped from the hallway, Nick comes up with a plan. The mortal realm has a magnetic field, as does Hell. If they could reverse the realms’ polarities, they’d start repelling each other.
Sabrina Spellman, Zelda, Hilda, and Nick stand at the epicenter of Hell while Sabrina Morningstar, Lucifer, and Caliban stand at the epicenter of the mortal realm. Ambrose and Mambo Marie watch from the Observatory as the others summon their opposing energies. Ambrose and Mambo Marie continue to examine the two colliding realms. Unfortunately, they are too enmeshed, similar to conjoined twins. Ambrose fears that they might end up destroying both realms and orders the Order of Hecate and the Morningstars to stop the invocation.
Theo tells Robin that he can’t leave his dad and friends behind, so Robin decides to stay in the mortal realm as well, saying goodbye to Moth, who watches from outside the window.
Melvin reveals to the Spellmans and the Morningstars that it is raining pearls. Ambrose realizes that these pearls come from the pearly gates, meaning that the celestial realm is falling on top of them. Metatron, an angel from Heaven, arrives. Lucifer explains that Metatron is of the highest celestial order, as close to the False God as he once was. Metatron represents order and there is an unprecedented amount of chaos in the cosmos, so they've come with a solution to restore order. For the cosmos to survive, one Sabrina must die or merge together as one.
The two Sabrinas contemplate whether or not to merge. If they agree, the realms would remain intact and no one would die because of them however they also fear the outcome of the two of them merging, with one Sabrina simply being absorbed by the other. Nevertheless, they agree to the merge but want time to get their affairs in order, for Morningstar to spend her last moments with her friends and for Spellman to spend some time with Nick. Ambrose doesn’t support this decision but there’s no other way. Sabrina asks Ambrose if he can still repair the telescope and give it to Roz. It will be her legacy at Baxter High. Metatron then grants Sabrina Spellman and Morningstar six hours before the merge.
Hilda enters Lilith’s room to inform her that Lucifer is at the Academy. Hilda wants Lilith to pack and flee, but Lilith refuses to run. She asks Hilda to hide Adam and send in Lucifer.
Lucifer and Caliban meet with Lilith, who has sent Adam away. Lucifer reveals that he will be taking his son when he leaves for Hell. Looking to take the attention off her, she informs Lucifer that Caliban sent the kings to kill her, but he denies any such doing. Not that it matters, as Lucifer couldn’t care less about Lilith. He would kill her, but he doesn’t want to make her a martyr to their son. As Romulus and Remus suckled on the teat of a wolf, so his son will suckle on the teat of a hellhound, Lucifer says. Lucifer orders Lilith to retrieve their son and ensure that he’s ready when Lucifer returns to take him in six hours.
Sabrina Morningstar spends her last hours with Harvey, Roz, and Theo. The four of them perform Turn Around in Harvey’s garage. Meanwhile, Sabrina Spellman invites Nick over. Even after everything that happened between them, she still misses him. She reveals that the 1% chance he was referring to is now and the two proceed to have sex.
Lilith tells Adam that he’ll be alright and that Lucifer will never have him.
Moth intercepts Theo on his way home and tells him that he's ruining Robin’s life. Robin belongs with his own kind. He’s as fast as lightning and can live for thousands of years, but the longer he stays in the mortal realm, the weaker he becomes. Eventually, he won’t be a hobgoblin at all. Moth tells Theo to let Robin go for his own sake.
Ambrose fulfills Sabrina’s final request and repairs the telescope, during which time he makes a startling discovery.
Their six hours are up and Sabrina Spellman and Morningstar return to the Academy, where they are comforted by Nick and Caliban, respectively. Metatron begins the merge. As they begin to come together as one, Ambrose interrupts to inform Zelda and Hilda that there are three new realms approaching, on a collision course with their own. They are the next Eldritch Terror, bearing down upon them, causing these tremors, promising their extinction. They are horrors from the stars, otherwise known as the Cosmic. Ambrose and Lucifer accuse Metatron of knowing and withholding this information from them. Metatron admits this is true. Had they known of the duplicate cosmos, there was an 83% chance that they would’ve tried to preserve both Sabrinas lives, with the probability of that being successful being just above 0%. Metatron insists that the merge must proceed or else the rogue cosmos will destroy their three realms. Nick asks for the probability of the merge succeeding, which is only at 56%. The Spellmans and the Morningstars work together to prevent Metatron from completing the merge and snap their neck.
Ambrose and Mambo Marie explain that there are three duplicate realms approaching their own. The existence of two Sabrinas in their cosmos has brought about the existence of a parallel cosmos that is being pulled towards theirs by the two Sabrinas. They could avert this deadly impact and cause the Eldritch cosmos to dissipate by sending one Sabrina from their earth to the other earth. Zelda and Lucifer argue over which Sabrina will go to the other Earth. Spellman and Morningstar have decided to settle this with Rock, Paper, Scissors, a game that Spellman wins, and so Morningstar must go to the other Earth.
With tears in his eyes, Theo tells Robin to leave for the fay realm with the other hobgoblins. Theo exclaims that he doesn’t want Robin anymore and pushes him to leave. Before leaving, Robin tells Theo that he loves him and to leave his window unlocked for one day he will return and come back through. After Robin leaves with Moth, Theo locks his window.
Sabrina Morningstar kisses Caliban goodbye and tells him to honor her promise to her. She then says goodbye to Spellman. Morningstar asks Ambrose what the other universe will be like. If not an exact copy, it’ll be at least very close to their own. Ambrose and Nick then open up a portal in a mirror and send her through.
Sabrina Morningstar exits the mirror on the other side. She is approached by her aunts, who don’t look the same despite Ambrose claiming that the universes would be near identical.
Lucifer returns for his child only to discover that Lilith has killed their son, Adam. She had made a meal out of him similar to what Lucifer did to Adam Masters. Lilith explains that she’d rather their son die than for him to be raised in Lucifer’s image. She then begs him to kill her. Lucifer would rather see Lilith suffer, so he strips away her powers and banishes her to walk on Earth for the rest of her days as a mortal.
Prudence tells Blackwood to help them stop the Cosmic or else her next needle will go through his ear.
Nick finds Sabrina standing by her window with regret and concern for Morningstar. They see a falling star and Sabrina wishes that everyone remain safe.
- The episode title refers to a specific phrase; a plot device whereby a seemingly unsolvable problem in a story is suddenly and abruptly resolved by an unexpected and unlikely occurrence.