The Identity of "A" Was Finally Revealed in the "PLL: Original Sin" Season Finale

In the end, it's revealed the Liars' school principal, Marshall Clanton, was A all along. While the revelation comes as a shock to viewers, it's not entirely out of left field. Principal Clanton was seemingly waiting in the wings throughout the entire season. For example, it explains why the masked killer could roam around the school, evading notice. It also explains why A was in the know about everything the Liars were discussing and planning throughout the season.

So, what was Clanton's motive? It turns out Clanton is Angela Waters's father. He grew up with Rose Waters in Millwood and they fell in love while in the school choir together. When Rose became pregnant, Clanton's parents didn't approve, so they paid Rose off, and she disappeared. Clanton went on to become the principal of Millwood High. Years later, Rose returned to the town because she wanted Angela to go to Millwood High. Clanton agreed, as long as Rose kept his paternity a secret. From then on, Clanton had a front-row seat to the mothers' mistreatment of Angela and became A to exact revenge on them after her suicide.

But Clanton had some help.

Turns out, Rose wasn't just pregnant with Angela. She gave birth to twins, and named Angela's brother Aaron. Angela's sibling didn't attend Millwood High with Angela because Rose believed he had a face "only a mother could love," according to Clanton. After Angela's death and Rose's mental breakdown, Clanton raised Aaron in secret, and they worked together to avenge his sister.

At the end of episode 10, an injured Aaron escapes from the local hospital and goes to Chip's house to kill him for raping Tabby and Imogen. While it's unclear if he succeeds in killing Chip, it's obvious that Aaron will be on the loose if "PLL: Original Sin" is picked up for another season.

There was never any doubt the Liars' mothers, who, at one point, were friendly with Angela, had something to do with her tragic suicide at the NYE party.

It seemed possible one of the five friends resented the rest of the group for being awful to Angela and decided to exact revenge on them as a way to assuage the guilt she harbored.

Since Davie dies in episode one, and every passing episode reveals the specific ways each mother relentlessly bullied Angela in the past, the only mother whose history with Angela lent itself to this theory was Sidney (her only crime against Angela was doing nothing to help her). But in the end, this simply wasn't the case.

One Twitter user theorized Angela's disheveled look in the flashback sequence might be due to her giving birth to a baby moments before the Y2K party and that it was her secret child who stepped up as "A."

As Twitter user @_davitron_ explained: "in 1999, Angela waters and davie adams were best friends. davie was dating tom beasley. tom and angela had sex and she got pregnant. the night of the rave, angela gave birth and ran to her friends to help her. they (specifically davie) refused. as a result, angela died. now, angela's baby is grown, and is targeting the parents (and their children) who are responsible for A's mother's suicide. that's why A killed davie. it was extra personal."

They added that Davie's guilt over Angela's death might've fed into her wanting Imogen to keep her baby and raise it together as a redo. Per the theorist, Angela's son may have targeted Karen first due to his grudge against Tom, who chose to raise his daughters while abandoning him and Angela. Additionally, in episode five, we find out that Angela's mom, Rose, was visited by a sixth person (other than the Liars' moms) while she was at the Radley Sanitarium. Could the mysterious visitor have been Tom, aka, the theorized father of "A"?

While it turns out Sherriff Beasley does have an awful connection to Angela (he raped her to "prove" he was straight to his friends when they were in high school), Angela never had a secret child.

Chip seems like the perfect friend to Tabby throughout the season, but almost too perfect. He never gets annoyed with Tabby, even when she only agrees to go to the dance with him if he helps her embarrass Karen in front of the whole school or when she straight-up calls him a bozo for his taste in horror movies. His unrequited feelings for Tabby would also play into why "A" killed Tyler after his fight with Tabby at the Halloween party.

Additionally, he sets his sights on Imogen beginning in episode seven. He shows up at the exact moment her fake baby for their school assignment goes missing to help her find it (and it conveniently has a message from "A" tacked onto it when they do). Then, he enthusiastically pretends to be the father of her baby when he tags along with her to see a social worker about the possibility of giving her child up for adoption.

The identity of Imogen's baby's father is a mystery until the final episodes of the season, and considering she was attacked in a way that was similar to her best friend Tabby, it seemed like there was a chance something even more duplicitous was going on under the surface.

In the end, it's revealed Chip is, indeed, Imogen and Tabby's attacker and Imogen's baby's father. Despite him being a totally sick and disturbed individual, he has nothing to do with "A" and their plot for revenge.

Millwood High's ballet teacher is ruthlessly harsh with her students, but she's especially cold toward Faran. For starters, Madame Giry, who Faran accurately describes as "the adult version of Karen," very casually slips in a sugarcoated threat about disclosing Faran's medical history with scoliosis, which could jeopardize her chances at getting into her dream school.

Also, when Faran spots "A" creepily keeping tabs on her during her practice session and follows them, the next person she bumps into is none other than Madame Giry. Not to mention, her physical stature fits the person rocking A's overalls.

Seeing how freely "A" moved in and out of the school suggested A had a connection to someone with access there, but it turns out it was never Madam Giry.

Since someone in Angela's life was consumed by their thirst for vengeance against people who contributed to her suicide, it seemed reasonable "Crazy Joe" could be that person. In episode six, it's revealed "Crazy Joe," the classmate of Angela who reaches out to Imogen to tell her about Angela's time in high school, used to have a crush on her in school and resents the Liars' mothers for their mistreatment of Angela. In the end, while "Crazy Joe" was helping Principal Clanton and Aaron, he isn't "A."

Given "PLL"'s long-standing penchant for twin twists, it seemed there was a chance the Beasley sibling who died during the Spirit Queen ball was actually Kelly, not Karen. One viewer noticed that the movie references on the show may have subtly hinted at this twist.

Reddit user @achterlicht noted that the four movies that screen at the Orpheum where Tabby works are "about people pretending to be someone else, some more direct than others." The titles in question are "Body Double," "Dressed to Kill," "Get Out," and "Us." They added that another reason this theory was not so far-fetched is the fact that Imogen mistook Kelly for Karen at the dance, which may not have been a mistake. After all, the two were best friends and were past such "twinfusions," as Kelly pointed out.

Let's not forget that it was Karen who delivered the flyer of the 1999 rave to Davie in the premiere episode, saying it was taped to their front door.

Despite all these signs, it becomes clear early on that Kelly can't be "A." Faran becomes convinced Kelly is actually Karen in episodes four, five, and six. At the Liars' Halloween party, "A" is spotted watching the pair argue about that very thing, and they attack Kelly while she's practicing ballet in episode six. Jury's still out on whether Karen stole Kelly's identity, but she's definitely not A.

On more than one occasion, the show hints that Kelly lives in Karen's shadow, even dressing up as Karen to do her bidding at one point or staring just a tad bit too long at a photo where Karen and Imogen are cuddled up close while she's off to the side. Could she resent her sister for outshining her? Considering Kelly was attacked by "A" in episode six, it became clear she wasn't "A" either.