AceShowbiz -

Having answered the big question about who "A" is, "Pretty Little Liars" is ready to introduce a new mystery when the show returns in early 2016. As teased in the summer finale which aired on Tuesday, August 11, the Liars were warning Alison about someone who's after her.

Showrunner I. Marlene King says the person that the Liars were talking about could be the new "Big Bad" on the show. "You have to wait and see!" she says when asked by The Hollywood Reporter about who's after Ali. "But there is a Big Bad in this new world that we're creating as we move forward, and the Liars are talking to Ali about the person they suspect to be this Big Bad."

She also tells Entertainment Weekly that the newly introduced mystery "is definitely brand new, but there's some connection to the past. Not a mystery revolving around the past, but a connection to the past."

Following the "A" reveal, the show jumped ahead five years. What happened to the girls during those five years? King reveals Ali's "gotten married. ... And she went to college at Hollis so she could stay close to Charlotte. Hanna's engaged. ... And the girls have spent five years apart - they've had five 'A'-free years of life just to live a normal life."

Other characters that will return in season 6B include Sara Harvey, Lucas, Melissa, Ezra, Caleb, Toby, Jenna and the girls' parents. Charlotte a.k.a. CeCe will also be part of the story and she "definitely is working to get better when we see her next."

There's also a wedding coming up this season, but King says "it's not necessarily Hanna" who is getting married. Further teasing what's in store for the second half of season 6, King says "something happened to Sara Harvey that we're going to find out about when we come back. She's a little bit of a mysterious character in our world, and it's going to be fun to watch that play out."