In the new series, five high-school girls – Imogen Adams (Bailee Madison), Tabby Haworthe (Chandler Kinney), Faran Bryant (Zaria), Minnie “Mouse” Honrada (Malia Pyles) and Noa Olivar (Maia Reficco) – bond as A launches a terrifying campaign against their mothers to punish them for their past offences.

Slowly, the girls uncover the truth about their mothers and the other kids at their school.

Co-creators Roberto Aguirre-Sacasa and Lindsay Calhoon Bring wanted to preserve the “DNA” of Pretty Little Liars while keeping the show fresh. By paying homage to slasher films from the 1970s and 80s, they revitalised the franchise, embracing the scare factor of A while retaining the central focus on female friendship.

Bring, who grew up on horror fare like Tales from the Cryptkeeper and A Nightmare on Elm Street, came to Aguirre-Sacasa – whom Warner Bros. had asked to develop a new version of Pretty Little Liars – and suggested they work together to integrate the slasher element into the show.

“I love slashers, [but] I’d never done a slasher. The second that she brought that up, I was like, ‘I can see that, and I understand why I would be a person working on it,’” Aguirre-Sacasa says.

Along with the mystery of A’s identity and following the conventions of teen drama, each instalment prompted the pair to ask, “What is the slasher-horror set piece in this episode?” Aguirre-Sacasa recalls.

To achieve this consistently, they sought out images and sequences designed to give A that slasher villain edge: the sight of a mysterious figure across a cemetery, a chase scene over rooftops.

They also overhauled A’s image. In previous iterations of Pretty Little Liars, A is seen lurking in a black or red hoodie. This time around, they wanted to give A the full slasher film treatment and create prominent “iconography” for the villain.

“One of my favourite factoids about Friday the 13th is that the mask isn’t introduced until the third movie, but we all remember Jason with a hockey mask,” Bring says. She adds that people tend not to call horror films by their titles, but by their leading villains.

For example, Freddy Krueger in A Nightmare on Elm Street. The creators wanted something similar for A.

They initially suggested a generic animal mask, like a jackal, but ultimately turned to director and production designer Lisa Soper to push the idea further.

“We really wanted to make sure that it was unique to A,” Soper says. “I probably went through 30 or 40 different mask concepts.”

She looked at other iconic masks and narrowed them down to their common traits: zero emotion, pale complexion, hidden eyes. She started “tearing back” elements of emotion from her initial designs, “deconstructing the mask and hiding who this person is.”

She landed on a flesh mask that “felt like it could have been victims that he stitched together,” Soper says. In between pieces of flesh, the letter “A” is subtly stitched and made prominent with staples.

But though Aguirre-Sacasa and Bring pulled liberally from popular horror tropes, they purposefully left one behind: the male gaze.

Chinese horror films are bad, but these five really bring the scares

“When we went back to those movies that we saw as teenagers, and probably before we were teenagers, you realise most if not all of these movies were written and directed by men and often are objectifying and exploiting young women,” Aguirre-Sacasa says.

In celebrating the genre, they wanted to also critique it.

Aguirre-Sacasa recalls reading about the concept of the “final girl” in the horror genre in Men, Women, and Chain Saws by Carol J. Clover. Audiences see the “final girl” tormented to the very end – a victim of sadistic oppression and harassment. Bring points to the “gratuitous” shower scene in [the 1976 horror movie] Carrie as an example.

Though Original Sin occasionally flips the script in more alarming ways, such as Tabby’s secret filming of the boys’ locker room, it also attempts to “empower” the series’ female characters through its aesthetic choices, Soper says.

“Generally, when you film a woman, you’re at a slightly higher angle, looking down on them. With these girls … we would take the camera down a bit and look up,” she says.

She also assigned each girl a highly symbolic weapon. Imogen was the knife, Tabby was the hammer, Faran was the bow, Noa was the shield and Mouse was the trap.

“These girls were able to play with them individually and use that symbolism to help drive their characters to fight the slasher villain,” Soper says.

Despite this new iteration straying far from its predecessors its genre and tone, the team behind Original Sin believes it’s in keeping with the beloved original – especially in upholding the bond between the girls.

“We love the original Pretty Little Liars,” Aguirre-Sacasa says. “We wanted to honour them and create something that old fans and new fans could enjoy without thinking, ‘Oh, you’ve taken this thing I loved and kind of denied it or smashed it or redone it.’”

Slashed it, though? That’s a different story.