Pretty Little Liars: Original Sin | Season 1

 

"Chapter One: Spirit Week"

In 1999, teen Angela Waters commits suicide at a party after her pleas for help are ignored by everyone, including popular girls Davie Adams, Sidney Haworthe, Corey Bryant, Elodie Honrada, and Marjorie Olivar. Twenty-two years later, Davie receives an envelope with the flyer from the party and an ominous message written on the back. Her teenage pregnant daughter, Imogen, and Imogen's ex-best friend, Karen Beasley, find Davie dead in the bathtub with an 'A' scrawled in blood nearby, to Imogen's shock and confusion. Imogen moves in with Sidney and Sidney's daughter, Tabby, and a month later returns to school. After panicking about her future of raising the baby with no support, Imogen fights with Karen and decides to run against her for Spirit Week Queen and also receives a mysterious message from an unknown person. Meanwhile, Tabby promotes a double feature screening at her workplace, the Orpheum; like Imogen, she soon receives a strange text. Fellow students Noa Olivar, Minnie ‘Mouse’ Honrada and Faran Bryant also receive similar messages. Meanwhile, a masked figure is watching them. The figure murders a school janitor who found the former's secret lair. Imogen, Tabby, Noa, Mouse, and Faran end up in detention for multiple incidents against Karen. Thinking that Karen framed them, they agree to get revenge against her.

"Chapter Two: The Spirit Queen"

The Little Liars devise a plan to humiliate Karen after Imogen shows them an embarrassing video of Karen. Tabby suggests to play it during the double feature at the Orpheum, so no one can record it. Students gather at the Orpheum for the movies; the video is played before the first film and an humiliated Karen flees, followed by her twin, Kelly. Kelly, impersonating Karen, confesses to Principal Clanton that she was the one that committed the crimes The Liars were punished for, but this was just the twins' plan to get back at Imogen for the video. Karen drops out of the spirit queen race. The girls arrive at the dance, and the principal announces Imogen as the spirit queen. Previously, Kelly proposed to get revenge at Imogen by pouring a bucket of red paint on her while she receives her crown.[a] Before the plan is executed, the girls see Karen hiding in the rafters and try to warn Imogen. Imogen heeds their warning and looks up to see the masked figure push Karen to her death. The girls receive a text message from "A", who killed Karen for being a bully and threatens them to keep silent or they'll be next.

"Chapter Three: Aftermath"

Shortly after the bloody incident, Imogen informs the girls that a masked figure pushed Karen to death, and they reveal to have also seen the figure. Scared to tell the truth, Kelly suggests to Tom that Karen may have committed suicide due to the embarrassing video. An angered Tom is determined to punish the girls. Imogen discovers a news about Angela Waters, a teenager whose body was found days after her death in 1999, in an abandoned warehouse. She visits the warehouse, and soon the masked creeper arrives. While revisiting the warehouse with Tabby, Sidney arrives and explains what happened to Angela the night of the rave, but lies about other details. Noa tries to convince Faran and Mouse to blame Karen's death on Imogen and Tabby after the Sheriff harassed her, but eventually sides with them. Noa reveals to Shawn that she took the blame for her mother's drug use. After telling her father the truth, Kelly meets with Imogen and apologizes for her actions, blaming herself for Karen's death. The Little Liars visit Karen's grave with their own personal messages for her, as the masked creeper is watching them from his van.

"Chapter Four: The (Fe)male Gaze"

In 1999, Marjorie convinces Angela to smoke, but blames her when they got caught and later gives her a friendship doll. In 2022, Marjorie receives the same doll with taunting messages. Tabby and Chip partner for a film project, recreating the shower scene from Psycho and asked Faran & Greg to act. Greg's actions during filming triggered Tabby, who has blurry visions about a party in the woods. Faran begins to believe that Kelly is actually Karen and asked Henry to investigate, since Karen would have a scar on her foot due to the razor blade put on her shoes. During a visit by Sheriff Beasley to the Olivars' apartment, he finds drugs and Marjorie quickly blames it on Noa, who managed to swerve. Later, the masked creeper chases Noa on the building and forces her to "punish the guilty". She reluctantly called the hospital and told them Marjorie has been stealing drugs.

"Chapter Five: The Night He Came Home"

In Halloween 1999, Davie and her friends convince Angela to throw dog feces at a house, but leave her. Tabby is angered by Chip, who finished their project without her, since she wants it to be taken from the female gaze; he apologizes and offers to reshoot the scene together. Henry tells Faran that Kelly indeed has the scar Karen would have, convincing her even more that Kelly is actually Karen. However, Madame Giry reveals that Kelly has self-harmed in the past, and a regretful Faran tries to befriend her. Unwilling to sell her house due to unanswered questions, Imogen plans to throw a fundraising Halloween party. At work, Tabby is harassed by a jock and fellow student, Tyler, who later harasses Minnie at Imogen's party. The masked creeper, who has been lurking around Imogen's house, wears the mask Angela wore in 1999 and kills Tyler. After witnessing Kelly kissing Greg, Faran again accuses her of being Karen. Mouse meets with Steve whose daughter, Rachel is missing and roleplays as her. After the party, Tabby and Imogen reveal to each other that they both have been sexually assaulted.

"Chapter Six: Scars"

Tabby recounts the night she was drugged and raped but reveals to Imogen that she does not know the identify of the assailant. Imogen also confides that her pregnancy was a result of being raped the night of Karen's party but does not remember due to being heavily intoxicated. The two meet with Joseph England, a former classmate of their mothers, and learn that Angela's mother, Rose, was committed to Radley Sanitarium after Angela's suicide. After further investigating, they learn that Angela was raped and that Rose was visited by Sidney, Davie, Elodie, Marjorie, Corey, and a sixth unknown person. Meanwhile, Noa fails to convince Marjorie to attend rehab and Steve begins stalking Mouse. Faran and Corey's relationship is further strained after they both receive messages from "A" that reveal Faran's corrective scoliosis surgery was not necessary.

"Chapter Seven: Carnival of Souls"

As the Millwood carnival approaches, Mouse and Tabby each struggle with secrets, and Noa notices Shawn isn't himself. Meanwhile, Imogen considers her baby's future, and Faran confronts everything that's been plaguing her.

"Chapter Eight: Bad Blood"

The friends attempt to get to the bottom of one mystery, while Imogen pursues answers to another. Then, a much needed girls' night prompts Sidney to confront her daughter about a long-held secret

"Chapter Nine: Dead and Buried"

The Liars meet up with the mothers explaining Joseph's recent death. Joseph was also in love with Angela and may have been "A". It is revealed that Sidney, Davie, Elodie, Marjorie, and Corey bullied Angela in high school. Tabby and Imogen start to believe that "A" killed Crazy Joe and is still free. During breakfast at the Beasleys', it is revealed that Kelly is not supported by her parents and the Sheriff reveals that it should have been Kelly who slipped and not Karen. Imogen contacts her father to get written permission to exhume Davie's body in order to prove that she was murdered. The girls hear from Marjorie's clinic that there is a match for the DNA from the blood drive. Faran confronts Sheriff Tom and says that he needs to stop emotionally abusing Kelly and that he needs to resign as a Community Service leader due to Noa's allegations. Imogen learns from her father that her mother Davie used to date Tom Beasley in high school. After Faran's father is arrested, she goes to the Beasleys', revealing Tom's obsession with young boys. Mrs. Beasley reveals that Sheriff Tom was the one who raped Angela.

"Chapter Ten: Final Girls"

Tabby and Imogen confront Chip, suspecting him to be their rapist. "A" listens as Chip admits his actions and chases after him. While investigating the Waters' house, the Liars find clues that make them think that "A" might be Angela's secret brother. The five receive a text from "A", who is holding their mothers captive at school. Martha stabs Tom after he reveals his plan to murder-suicide the family, and Kelly rushes to help the girls after Imogen sends her an emergency text. The Liars find their mothers tied up in a makeshift courtroom at the school gym. Principal Clanton is Angela's father and the mastermind behind "A"; the masked figure is Angela's twin brother, Archie. After Tom raped Angela, Davie made the whole school ignore her and pretend that she did not exist, eventually leading to her suicide. With Davie dead, Clanton decides to punish Imogen personally and sacrifice her. Planning to kill Imogen for avenge of Angela, Archie chases and attacks her, just as she begins going into labor. Kelly arrives with Greg, who is shot by Clanton. Tabby subdues him, and Imogen manages to take Archie down, her water breaking moments later. Tom survives the stabbing, while Clanton and Chip are arrested. The Little Liars and their moms help Imogen get to the hospital in time and her baby is born. Archie later escapes the hospital, killing Tom and the guard, and attacks Chip.