Once Upon a Time star Lana Parrilla recently discussed her character Regina's new half-sister storyline and dismissed one of the more popular fan theories.

Wicked Witch Ready To "Hurt People" In Next Episode?

Ever since the revelation that Zelena, a.k.a. The Wicked Witch (Rebecca Mader) is Regina's half-sister, fans have been discussing the idea that it may have been some elaborate trick by Zelena. Parrilla revealed to TV Guide in a Friday report that Regina really is Zelena's half-sister.

"As we move forward, other things are discovered, and we learn that she actually is her half-sister," Parrilla said. "It's quite jarring for Regina. She feels completely betrayed yet again by her mother. She's not too happy about it."

Snow & Charming's New Baby A "Savior" Like Emma?

Parrilla herself admitted that she found the half-sister twist rather outlandish.

"I thought it was wild and unbelievable and there has to be some kind of twist behind this because it doesn't quite make sense," she said. "The first time I read it, I was like, 'This can't be! I'm an only child!'"

She also teased that there will be another twist involved in the half-sister plot that may or may not have something to do with Regina being revealed as The Wicked Witch of the East to Zelena's West.

"There's an interesting twist that's coming up," she teased. "I wouldn't rule out that possibility."

Once Upon a Time season 3 airs Sundays at 8 p.m. on ABC.

Watch the promo for the next episode of Once Upon a Time below: