Nine months ago
In Boston, Vivien is ready to separate from Ben and take Violet to her sister's. They discuss a house Ben found online, which they would eventually live in. As they discuss, scenes and images to come flash onscreen.
In the present, Ben calls out for his wife and daughter wondering where they are.
Constance has been caring for the surviving baby, but is reluctant and evasive in giving him up to Ben. Vivien's sister has arrived for the funeral, and will be taking care of the baby. Constance warns Ben of the dire consequences of bringing the baby back into the Murder House, though Ben does not heed her warning. It finally becomes apparent to Ben that Constance is Tate's mother. He is angry that "she" destroyed his family, and threatens her.
Vivien and Moira chat about her adjustment. Moira reveals that Ben can't see her unless she wants him to. Vivien still believes Ben is a good father, but doesn't want him to see her or Violet, lest he wants to stay. Moira reminds Vivien that they are equals now, and implies they should be friends in this new phase.
Ben, distraught over the death of his family, and prepares to commit suicide with a revolver. Vivien suddenly appears and takes the gun, telling him she wishes he would leave the house and raise the child elsewhere. He acknowledges that it is probably not even his baby. Violet also appears, and they both plead with him to leave. Vivien kisses him goodbye, and they vanish.
Some time later, Stacey and Miguel Ramos tour the still furnished house with Marcy. Marcy carries Hallie (whom she has adopted) around. They continue touring the house, while their son Gabriel skateboards around the dining room. However, his trip is cut short by the mischievous and troublesome twins Troy and Bryan. Stacy and Miguel are very excited, and decide to buy the house.
Meanwhile, homicide detectives question Constance, who says she refuses to go back in the house after discovering Ben's body. The Harmons, all ghosts now, rejoice. Hayden refuses to hand over the living child, but Travis slits her throat, handing him over to Constance. The detectives are lead to believe Violet ran off with the child, when in reality the baby is being hidden in the "bad girl closet".
Violet visits Gabriel and criticizes his taste in music. She flirts with him and slyly hints at her ghostly existence while Tate watches, filled with jealousy and rage.
The elder Ramos' redecorate the kitchen, and grow intimate, watched by Ben and Vivien, who are keeping their presence hidden. Miguel suggests they have another baby. Ben, Vivien, and Moira plan to not allow the family to being subject to the pain and misery brought upon by the more malevolent ghosts who only wish to inflict their fate on the living.
Miguel awakens to the sound of faint whispers. Rubber Man attempts to rape Stacy. Gabriel awakens to find Tate sitting at the foot of his bed, and suggests he is dreaming about Violet, from whom he is still estranged. A frightened Stacy attempts to fight off the Rubber Man, while Miguel sleepwalks, and is drawn to the stove. As Stacy attempts to flee from the Rubber Man, Beau jumps from the attic, scaring her into the bathroom. Tate proceeds to fight Gabriel. Many of the spirits trapped within the house make their presence known. Gladys appears to Stacy, while a Younger Moira and a bisected Elizabeth appear to Miguel which causes him to snap out of his trance. He follows Stacy's screams to the basement. Vivien angrily guts Ben, and remarks how long she has wanted to do so. He responds by shooting Vivien in the head, with the same response. They collapse, giving the impression they are dead, and arise, urging the Ramoses to leave and never return. It was all an effort to scare them away, but Tate is not playing the same game. He actually wants to kill Gabe, so that Gabe can be with Violet and keep her company as the "normal boyfriend" that Tate could never be for Violet. He attempts to kill Gabe, but cannot bring himself to go through with it. The killer doesn't have it in him anymore. Violet stops his attempts by distracting Tate with a kiss. She wants a proper kiss goodbye, which gives Gabriel the opportunity to escape. When she vanishes, Tate begins breaks down weeping in his old room. The Harmons celebrate their success, and decide to dedicate the rest of their existence, preventing anyone else from moving in and falling victim to the house's evil forces.
The Eternal Darkness Tour now covers the Harmon history, much to the consternation of Marcy. Tate confronts Ben, pleading for his forgiveness and mercy. Ben tells him that therapy never really works anyway and calls Tate out for being a psychopath, believing that he is incapable of feeling true remorse and is only putting on an act. Tate confesses to all his actual misdeeds, which includes setting Larry on fire, killing 15 of his classmates, murdering Chad and Patrick, and impregnating Vivien. Ben can't find it in his heart to absolve him, but all Tate asks of Ben is companionship.
Vivien resumes playing the cello for the first time in a while, when she is suddenly alarmed by a baby's cries coming from the basement. Nora rocks Vivien's "stillborn" baby, who actually lived for a few moments before dying. Nora strongly reminds Vivien the baby is hers (Nora's), and that "arrangements were made" to extract the baby from "help". Nora refers to him as, "Little Noisy Monster". Vivien quiets the baby with song, and Nora decides to take a rest. She admits she probably is not cut out to be a mother. Vivien walks with the baby, trying to decide on a name.
Moira cleans the house, and Vivien shows her the baby. Moira laments that she might have made a good mother, and Vivien asks her to be his godmother.
Around Christmas time, the Harmons and Moira are seen enjoying each other's company for the first time since moving in, showing they no longer take each other for granted. Meanwhile, Hayden and Tate watch the family through the glass doors in the dark. Hayden tells him that Violet will never take him back, or even talk to him again. Tate responds resolutely that he'll wait for Violet forever if necessary.
Three Years Later (2014-2015)
Helen, a beautician, greets Constance in her salon. Constance says that she has been housebound with her newly adopted baby (from distant cousins in Virginia). She has named him Michael. She confides that she has always known she would be destined for greatness, despite her tragedies preparing her.
When she returns home, she looks through her bloodied house to find her murdered housekeeper, presided over by a smirking and bloody Michael sitting on a chair, looking very pleased with himself. "Now whatever am I going to do with you?", she croons, showing her satisfaction as the "mother" of the prophesied "Anti-Christ".
Jeffery Harmon is the son of Vivien Harmon and Ben Harmon, and the brother of Violet and Michael. He was conceived in "Pilot". He was believed to be a stillborn (in "Birth"); after birth, he managed to take one breath, dying seconds later, making him one of the house's spirits. Nora Montgomery hustled him away, but proved unable to care for him. Nora didn't name him, preferring to call him "Noisy Monster". Vivien posed as a nanny, soothed him with a song and took him upstairs where she named him Jeffery. Jeffery is seen with his family at Christmas time, finally in a happy environment.
Michael Langdon is the "adopted" son of Constance, and the birth child of Tate Langdon and Vivien Harmon. He was conceived in "Pilot" when Tate, as the Rubber Man, raped Vivien, who she believed to be her husband, Ben. Billie Dean believed that a child born under these circumstances would be the Anti-Christ and would bring about the end of days. In "Birth," Vivien gives birth to him and his twin brother (named Jeffrey). He is quickly snagged by Constance. She and Moira admire him while washing off the placenta and Hayden comes in and states that he is her baby. Hayden enlists the help of Dallas and Fiona and kills Ben to prevent him from leaving with the baby and takes Michael for herself. Thanks to Travis incapacitating Hayden, Constance takes the baby from her and "adopts" him. In an epilogue, Constance comes home to find that Michael has murdered his nanny.
Miguel Ramos and his family move into the Murder House shortly after the death of Ben Harmon. The Harmons, along with the other good ghosts, band together to scare the Ramos family out of the house so that they can avoid the same fate as the Harmons and other families before them. That night, Lorraine Harvey causes Miguel to sleepwalk to the stove, in a similar fashion as Ben did in the Pilot episode. Soon, Miguel is led into another room by the younger Moira, where he sees the dismembered body of Elizabeth Short on the table. Miguel and Stacey soon run into the basement where Vivien and Ben (in the Rubber Man suit) corner them. Vivien disembowels Ben, while he shoots her in the head. This is the last straw for Miguel and Stacy as they flee the house.
Stacey Ramos moves into the murder house with her husband Miguel and son Gabe after the death of Ben Harmon. The Harmons and the other good ghosts in the house conspire to scare away the new family so that they avoid the same fate as they and the families before them. While Lorraine Harvey makes Miguel sleep walk into the kitchen, Ben goes into Stacey's room disguised as the Rubber Man in an attempt to scare Stacey. Stacey manages to fight him off and run out of the room where she runs into a multitude of good spirits such as Gladys and Beauregard. Eventually, Ben and Vivien corner Miguel and Stacey in the basement where Vivien disembowels Ben, and Ben shoots Vivien in the head. The Ramos, who have had enough, flee from the house.
Gabe moves in to the murder house with his family, and comes off as a typical skater guy. He interacts with Violet, who criticizes his taste in music, and hints at her ghostly nature. Tate becomes jealous of how "normal" Gabe was, and wants to bring him over as a ghost for Violet's companionship. However, when Tate is about to kill Gabe, Violet arrives and kisses Tate, giving Gabe a chance to escape with his parents. He manages to escape with his parents.
Helen is Constance's hairdresser. She hasn't been visited by Constance for quite some time, explaining the reason for her absence is taking care of her new child, Michael (which in fact is her own grandson). She is the person that Constance confides to about her realization that her reason for existence is being the mother of Michael.
- Hayden to Tate Langdon: "Grow a pair. She's not into you. You're not getting back in her, she'll never talk to you again."
- Tate Langdon to Hayden: "I'll wait... Forever if I have to."
- Ben Harmon to Tate Langdon: "You're a psychopath, Tate. It's a mental disorder, and therapy can't cure it."
- Kate Mara as Hayden McClaine
- Charles S. Dutton as Detective Granger
- Frances Conroy as Moira O'Hara
- Alexandra Breckenridge as Young Moira O'Hara
- Lily Rabe as Nora Montgomery
- Christine Estabrook as Marcy
- Michael Graziadei as Travis
- Anthony Ruivivar as Miguel Ramos
- Lisa Vidal as Stacey Ramos
- Malaya Rivera Drew as Detective Barrios
- David Anthony Higgins as Stan
- Brennan Mejia as Gabe Ramos
- Rebecca Wisocky as Lorraine Harvey
- Kyle Davis as Dallas
- Azura Skye as Fiona
- Jamie Brewer as Adelaide
- Meredith Scott Lynn as Helen
- Mena Suvari as Elizabeth Short
- Celia Finkelstein as Gladys
- Sam Kinsey as Beauregard
- Bodhi Schulz as Troy
- Kai Schulz as Bryan
- Asher Gian Starita as Michael Langdon (toddler)
- Ocean Maturo as Michael Langdon (baby)
- Denis O'Hare (Larry Harvey) is credited but does not appear.
- It's been said that the episode would be cut down from 120 minutes to a 90 minute special due to scheduling issues. However when it was broadcast, it was actually cut down to 70 minutes. There has yet to be an explanation for this.
- Seven babies were cast to play baby Michael Langdon, but the one used in the end was Ocean Maturo. 
- Commentary: Stack, Tim (2011-12-22). Ryan Murphy talks the game-changing season finale (en). Entertainment Weekly.
- ↑ Andreeva, Nellie (2011-11-18). 'American Horror Story' Two-Hour Finale Will Be Trimmed To 90 Minutes. Deadline Hollywood.
- ↑ Episode: Birth
- ↑ Spelling confirmed by the mother of the baby who was used for the show for both Jeffery and Michael on her Twitter
- ↑ https://twitter.com/#!/AHSFXBabyOcean