Warning: This story contains spoilers about the plot of Pretty Little Liars: Original Sin season 1.
Only the beginning. Pretty Little Liars: Original Sin ended its first season with many bombshells — but the HBO Max series also introduced new questions with A still at large.
“Twenty years ago, a series of tragic events almost ripped the blue-collar town of Millwood apart. Now, in present day, a disparate group of teen girls — a brand-new set of Little Liars — find themselves tormented by an unknown Assailant and made to pay for the secret sin committed by their parents two decades ago — as well as their own,” the synopsis for PLL OG: Sin read. “In the dark, coming-of-age, horror-tinged drama Pretty Little Liars: Original Sin, we find ourselves miles away from Rosewood, but within the existing Pretty Little Liars universe — in a brand-new town, with a new generation of Little Liars.”
Even though the two shows weren’t directly related, it wasn’t long before the story lines connected onscreen. While trying to track down answers about Millwood, Imogen (Bailee Madison) and Tabby (Chandler Kinney) end up visiting Rosewood — and hear about a connection to Riverdale in the process.
Creator Roberto Aguirre-Sacasa, who is an executive producer on The CW series, opened up about the decision to connect all three worlds.
“We kind of just wrote that line in,” Aguirre-Sacasa told TV Line in August 2022, referring to the onscreen mention of Riverdale‘s Sisters of Quiet Mercy. “I assumed that we wouldn’t be allowed to reference Riverdale, since it’s in a completely different universe, but it stayed in. So, yeah, I guess it does exist in the same universe. Bailee gives a great look when that’s mentioned. That was obviously just a fun Easter egg in an episode with the biggest Easter egg of them all, which is going to Rosewood.”
At the time, the screenwriter noted that other cast members were interested in a future crossover. “Alex [Aiono], who plays Shawn, is obsessed with the idea of a rivalry between the Millwood High Steppenwolfs and the Riverdale Bulldogs,” he continued. “I would love for there to be a football game between them. Who knows, though. If we did push it further, I don’t even know how far we’d be allowed to push the shared universes. It would great, though, that’s for sure.”
Aguirre-Sacasa also addressed the apparent continuity error of Lucy Hale portraying Aria Montgomery in Pretty Little Liars as well as the titular role in Riverdale‘s spinoff Katy Keene. (An episode of PLL: OG Sin name-dropped Cole Sprouse as well, who plays Jughead in Riverdale.)
“Both Riverdale and Cole Sprouse exist in the Pretty Little Liars universe,” Aguirre-Sacasa added. “It’s a multiverse!”
Scroll down for a full guide to each burning question that was answered in the PLL: OG Sin season finale: