Actress Sasha Pieterse from the ABC Family television series "Pretty Little Liars" in New York. (Brian Ach/Invision/AP)

“Pretty Little Liars” has hooked viewers with the twists and turns of four friends who are repeatedly tormented and tricked in their fictional town after their queen bee best friend Alison DiLaurentis is murdered.

That’s why many fans were shocked in the show’s annual Halloween episode, when it was revealed (spoiler alert!) that Alison was alive and had been in hiding this whole time.

The series resumed its fourth season this week, and actress Sasha Pieterse (peter-suh), who plays Alison, says even though “the girls find a little bit of satisfaction” in new episodes, all isn’t roses in Rosewood, Penn.

“There’s so much that they’ve been through, and to know that Alison was alive and didn’t do anything when certain things happen to them, I think that they’re going to have to deal with that because that’s painful, too. I think they’re happy that she’s alive, and probably pissed off,” Pieterse said with a laugh in a recent interview.

Now that we know Alison is alive, Pieterse will play a more prominent role.

Pieterse says the big questions now are, “Where has she been hiding, and who has she been hiding from?”

The 17-year-old South Africa-born actress is thrilled to be part of such a popular series.

“TV is so fickle. We get 24 episodes a season. That doesn’t happen as often anymore. It’s a great blessing to be working nine months out of the year.”

She recalls first auditioning to play the character of Hanna (the role went to Ashley Benson) and filming the pilot when she was 12.

The show is also popular internationally, with fans in the U.K., Brazil, France, and the Philippines.

For fans who can’t wait to see how the series unfolds, Pieterse suggests watching old episodes.

“If you go back and watch again, you’ll pick up little pieces,” she said. “There are things to find.”

— Associated Press

Pretty Little Liars

(one hour) airs Tuesdays at 8 p.m. on ABC Family.