"Pretty Little Liars: Original Sin" is a new upcoming American mystery-thriller television series. It is based on the popular "Pretty Little Liars" series of novels by Sara Shepard. The show is set to premiere on the streaming service HBO Max in 2022, and will consist of ten episodes.

Sean Walker plans to propose to his girlfriend Leila while they luxuriate on a Caribbean cruise. Instead, Sean suffers severe cruise interruption when Leila mysteriously disappears, and his desperate search for her leads him into a tangled web of inter-terrestrial intrigue. Equally desperate, disoriented, and terrified, Leila is trapped in an undisclosed location. "The Event" TV show fills-in the back-story as the current drama unfolds: As World War II drew to a close, an alien craft crashed in Alaska; government scientists determined the passengers were 99% identical to humans, but that radical 1% difference has the capacity to wreak havoc on the American population, among whom several of the survivors have been hiding and thriving. The CIA, naturally, has kept this information super-top-secret until technology beyond current human capacity foils an assassination attempt on President Elias Martinez. Which of these historic developments officially qualifies as "The Event" TV series remain approximately as uncertain as the reasons why Sean and Leila must forego serious tanning for all of this intrigue.

What started out as a web based series in Canada has turned in to a successful television program airing on the Sci-Fi network. We find that Dr. Helen Magnus (Amanda Tapping from The Outer Limits, The X-Files) and a team of experts run a place called Sanctuary where they examine and work with creatures and those people who have extraordinary powers, learning from them and hiding them away from harm. However some prove to be dangerous and must be handled especially carefully. Dr. Magnus is an English scientist who just happens to be 158 years old. She and her team of scientific experts run the organization seeking out assorted people or animals with special abilities and extraordinary powers. Dr. Magnus was trained by her father at a young age to protect the unusual and study the world. Her team includes her daughter Ashley, protege Will Zimmerman, Henry Foss a lycanthrope geek, and as a security and computer expert is one they refer to as Bigfoot (a Neanderthal like assistant played by Christopher Heyerdahl. Studying the abnormal each week includes run-ins with vampires, energy bound creatures, and competition from rival organizations.

When Scott McCall is bitten by a werewolf while he wanders in the woods, he tries to keep it his secret from all but his closest friend Stiles (Dylan O'Brien from High Road). Stiles willingly helps his pal Scott when he must go through changes and become a werewolf at night. Scott is played by Tyler Posey (Brothers & Sister, Lincoln Heights) and must undergo the changes even though he fights it. He is somewhat of a social outcast and having such an enormous secret other life, it is even more difficult to fit in at his northern California Beacon Hills High School. As Scott first notices how powerful he has become and how each of his senses has become heightened, he finds his shape shifting strangely intriguing. He loves the game of lacrosse and now plays like a pro thanks to his newly found gift of power. And romance is coming his way since he now has more self confidence and has found a girlfriend in Allison Argent (Crystal Reed from Skyline).

Remember Heroes' mindreader Matt Parkman, played by Greg Grunberg? The Listener's whole plot is passed on the same idea of secret power to read someone minds. Now this superpower belongs to Toby Logan (Craig Olejnik) a twentysomething orphan raised in the foster homes, who kept this secret with him all the time. But, when he shares it with his old councilor Dr. Ray Mercer, he starts his new life of as the part of Integrated Investigative Bureau (a special unit of the Royal Canadian Mounted Police) where he helps Detective Charlie Marks (Lisa Marcos) and E.R. Doctor Olivia Fawcett (Mylene Dinh-Robic) to solve crimes and difficult high-profile cases of murders and rapes. In his paramedical duties Toby is not alone; he works in cooperation with Osman Bey, his telepathic partner, who assists him in solving of most hard crimes IIB encounters. However, Toby's holy gift has the other, darkish side. Immersing in the minds of most inveterate criminals has terrifying side effects: Toby has to deal with heavy emotional and psychological impact of such of telepathic contacts. And here come his friends, helping him to deal with these issues: Dr Olivia Fawcet and other partners trying their best to keep Toby's mind working perfect as the secret weapon of IIB.

Detective Rebecca Madsen has a family history with the prison island Alcatraz and when fingerprints discovered at a grisly homicide case are found to be those of a diseased prisoner from years ago, Jack Sylvane, she becomes very interested in solving the case. The San Francisco Police Department detective teams up with an expert on Alcatraz history as well as a fan of comic book, Dr. Diego Soto, they attempt to piece the clues together and find out how an inmate in such a secure prison could still be alive and prowling the streets after all these years. It is soon discovered that Sylvane is involved in more murders and he may not be the only one to reappear from the inescapable prison known as The Rock, Alcatraz. Det. Madsen's grandfather and her surrogate uncle were both guards at Alcatraz while it was in operation and they know the dark past of that prison. Soon Madsen and Doc are joined by government agent Emerson Hauser and Lucy Banerjee, his technician. Hauser has been aware of Alcatraz' history and seems to have been waiting for something to happen. This series revolves around evidence that comes up and delves into the history of that infamous prison. Det Rebecca Madsen is played by Sarah Jones (Ugly Betty), the murderous Jack Sylvane is played by Jeffrey Pierce (Private Practice, Knight Rider), Sam Neill (Day Breakers, Jurassic Park) plays government agent Hauser, and Hauser's technician Lucy Banerjee is played by Parminder Nagra (ER, The Whole Truth).