After the Liars faced off with Charlotte in the midseason finale of "Pretty Little Liars," it looked like things were about to get better for Aria (Lucy Hale), Emily (Shay Mitchell), Hanna (Ashley Benson) and Spencer (Troian Bellisario) as they went their separate ways. But when the show returns, the four girls will be heading back to Rosewood after a five-year time jump, and they will be dealing with a new enemy who's deadlier than anyone they have ever faced.

In the "Pretty Little Liars: 5 Years Forward" special which aired last month, executive producer Marlene King and the cast talked about the show's return and the season's new big bad.

In the previous teaser trailers, it was revealed that the girls are now all grown up and are busy with their respective careers. Aria has become a writer, Hanna works in fashion, Spencer works in Washington D.C., and Emily is a bartender.

King explained how the girls ended up going back to Rosewood. While the four have established new lives and formed new friendships and relationships during their time away from home, King said that Alison (Sasha Pieterse) will be bringing them home because she needs their help regarding Charlotte.

"An event occurs that forces you guys to stay in Rosewood, and out of that event, a new big bad is born," said King to the four ladies in the ABC Family special episode.

Bellisario said that while they could not reveal what happens when the girls get back to Rosewood, she revealed that the Liars begin to receive messages again and they know that this time, it's not from Charlotte.

For now, it's anyone's guess who is the show's new big bad when the series returns next year. But one thing is for sure—the girls won't be taking the threats sitting down as King said that they will be fighting back and will be on top of the situation "right away."

"Pretty Little Liars" season 6B premieres on Jan. 12 on ABC Family/ Freeform.