Pretty Little Liars will soon have another meddling teen to worry about.

Prepare For 'Rapid Fire' 'Pretty Little Liars' Midseason Premiere, Liars Rally To Clear Spencer's Name

Rosewood seems to have its fill of troublemakers, but another piece of the 'A' puzzle will walk into town in the wake of Mona's (Janel Parrish) death. Named Lesley, the newbie will have strong ties to the recently deceased.

"In the episode where Mona met her demise, she was talking to her friend Lesley on the phone that day and we finally get to meet Lesley," said series creator Marlene King, according to E! Online. "She comes to town."

Will Emily & Alison Get Together On 'Pretty Little Liars'? Marlene King Talks Emison

It is unclear whether or not Lesley will drop by the murderous town simply for her friend's funeral, or if she will appear later in the season as a more permanent presence. Mona's funeral is slatted for the midseason premiere, "Through a Glass, Darkly," so viewers may get to meet Lesley sooner rather than later.

Considering Mona was chatting with Lesley on the day of her death, it is possible that Vanderwaal's pal knows something the Liars don't. Parish will return for several flashbacks over the course of season 5B, and perhaps some of these clips will involve Lesley.

Find out more when Pretty Little Liars returns to ABC Family on Jan. 6 at 8 p.m. ET. Click the video below to see a preview for "Through a Glass, Darkly."