Aria and Ezra Were Just Introduced Into the "PLL: Original Sin" Universe in a Major Way

The ultimate connection to the original "Pretty Little Liars" came in "PLL: Original Sin"'s season one finale, when Imogen tells Tabby a couple from Rosewood is adopting her baby. They're both writers, and their names are — wait for it — Aria and Ezra. Yup, as in Aria and Ezra from the original "Pretty Little Liars" and proprietors of Ezra's Books, the book store Tabby visited in episode six when the girls went to Rosewood to investigate Angela and Rose Waters.

While Aria and Ezra don't appear in the finale, the writing seems to leave the door open for them to pop up in the future, since Imogen says the couple is willing to give her updates on the baby's life. Not to mention, "A" is on the loose at the end of the finale, and considering he didn't succeed in killing Imogen and the baby, it's definitely possible he'll seek out the girl and her offspring in the future — pulling Ezria into "PLL: Original Sin"'s twisted web.

Speaking of Pennsylvania, episode six established just how close Millwood and Rosewood are.

Imogen and Tabby's investigation into Angela's past leads them to a place familiar to anyone who watched the original "Pretty Little Lars": Radley Sanitarium. So what brings our Milwood Liars to the town that started it all? Well, the girls find out Angela's mom, Rose, had a mental breakdown after Angela died, attacking a group of boys she believed sexually assaulted Angela before she died while they were at school. She was committed to Radley Sanitarium in the neighboring town of Rosewood after that.

"PLL" fans will remember Mona is sent to Radley Sanitarium after she's revealed as "A" in season two of "PLL," and by the end of the show's seven-season run, the sanitarium has been shut down and converted into a hotel. Imogen and Tabby visit the hotel to get information about Rose and Angela, where a familiar employee — Mona's friend, Eddie Lamb — explains that Rose was released to live out her life when the sanitarium was shut down and converted into the hotel.

After episode six, the Rosewood connections just keep coming. In episode seven, Shawn almost gets into a fight with jocks from Rosewood High School who crash their local town festival. While Noa breaks up the fight before it gets serious, the boys' blue letterman jackets with Rosewood on the back are unmistakable.

One of the main relationships that rises and falls multiple times throughout "Pretty Little Liars" is between Aria Montgomery (Lucy Hale) and Ezra Fitz (Ian Harding). The two meet and make out in a Rosewood bar, only to find out soon after that Ezra is Aria's high school English teacher. The pair embark on a forbidden romance spanning the show's entire run, "A" constantly lurking in the wings threatening to expose their secret.

"Original Sin" seemingly offers a more realistic (and decidedly creepier) take on Aria and Ezra's relationship in Tabby (Kinney) and Wes (Derek Klena). As Tabby's boss at the movie theater, when Wes isn't flexing his authority over Tabby, fawning over how "mature" her movie knowledge is, dangling his elusive NYU-film-professor connections over her head, or saying outright that he's interested in her, he's incessantly finding reasons to make her stay late at work and offer her rides home.

It has yet to be seen whether their relationship turns into anything romantic, but considering the original "PLL" was often criticized for the romanticization of a student-teacher relationship, it seems Tabby and Wes's relationship might be "Original Sin"'s attempt at a course correction.

The original "Pretty Little Liars" takes place in Rosewood, a small, nondescript, white-collar town in Pennsylvania. Fans of the franchise quickly learn that "Pretty Little Liars: Original Sin" takes place in Millwood, PA, another working-class town. The first "PLL" spinoff, "Ravenswood," is also set in Pennsylvania. The only "PLL" offshoot that moves out of the state is "The Perfectionists," which follows Ali and Mona (Janel Parrish) to a new college town in Beacon Heights, WA.

Overall, a Pennsylvania-small-town vibe seems to be the standard for "Pretty Little Liars."

"Original Sin" quickly establishes Karen Beasley (Mallory Bechtel) as the high school mean girl who bullies Imogen, Tabby, Faran, Noa, and Mouse for different reasons. Viewers also learn her identical twin, Kelly (also played by Bechtel), has a complicated relationship with her sister — one that isn't fully explained or developed before Karen is ultimately murdered by "A" at the end of episode two.

Fans of "Pretty Little Liars" will remember that when the original Liars think Ali is dead, it turns out to be the body of Ali's twin sister, Courtney DiLaurentis, and Ali is still alive, making "A" and Ali's backstory even more of a mystery.

The question of whether any of the original Liars will appear in "PLL: Original Sin" is still not answered, but the existence of twins in the spinoff mirrors this element of the original to an eerie degree. And because Kelly and Karen do switch places early on in "Original Sin," it begs the question of which twin actually died and which one is now choosing to help the Liars get out of trouble and solve the mystery of who "A" is.

The haunting opening lyrics of "Secret" by The Pierces in the "Pretty Little Liars: Original Sin" intro is something most OG fans will recognize by ear immediately. Behind a methodical accordion melody, the song playfully describes how some secrets are better left unsaid "'cause two can keep a secret if one of them is dead."

All seven seasons of "Pretty Little Liars" opened with the chilling theme song, so it makes sense that "Original Sin" uses a fresh, remixed version of the song for its intro.

"Pretty Little Liars: Original Sin" wouldn't be a "PLL" spinoff without the notorious "A," the main antagonist who harassed the Liars in the original show by threatening to reveal their deepest secrets. In the beginning, the Liars believe "A" is their former friend Alison DiLaurentis (Sasha Pieterse), who mysteriously went missing. She's the only one who'd know the secrets "A" is torturing them with, after all. But after Ali's body is found, they realize "A" has to be someone much worse. When signing cryptic messages of torment, the villain's signature is always "A" — short for Ali — and sometimes depicted in bright red.

The true identity of "A" isn't always consistent throughout "PLL," but the moniker sticks. Now, in "PLL: Original Sin," texts, notes, and even the first kill of Imogen's mother, Davie, are all signed with an "A," giving the new Liars their first clue as to who their tormentor could be.

In the original "Pretty Little Liars," "A" doesn't become a physical presence until later in the series, but the first three episodes of "Original Sin" establishes "A" as a tall, brooding, masked villain from the start. Another way the symbol is incorporated into "Original Sin" is through transitional graphics highlighting the passage of time, which feature every letter "A" in red.

OK, this isn't a "Pretty Little Liars" Easter egg, but almost anyone will recognize the many references to iconic horror movies sprinkled throughout "Original Sin."

From the bucket filled with red paint in the rafters of the school dance as an homage to 1976's "Carrie" to the small text Tabby gets from "A" quoting a line from 1996's "Scream," you can barely count the visual and verbal references on one hand. Additionally, much of Tabby's dialogue establishes her as a horror-movie buff who not only makes quick-witted references to movies but also dreams of attending prestigious film schools.

"Lindsay and I, as writers and creators, are fans [of the franchise]," Aguirre-Sacasa told TVLine about their deliberate callbacks to classic horror films. "We're fanboys and fangirls. We love this stuff. We love when characters [from other shows] pop in, we love the crossover episodes."

These are all the connections we've sussed out for now, but there are sure to be more as new episodes of "Pretty Little Liars: Original Sin" premiere on HBO Max on Thursdays this summer. Aguirre-Sacasa said, "Once you hit Episode 6, the Easter eggs — and more than Easter eggs — start coming fast and furiously, up to literally the last moment of the last episode."