Who is Charles? The girls on “Pretty Little Liars” are ready to get to the bottom of the mystery during Season 6, episode 3.

The synopsis for episode 3, titled “Songs of Experience,” reveals that the Liars will still be trying to recover from their kidnapping. Although Aria (Lucy Hale), Emily (Shay Mitchell), Spencer (Troian Bellisario) and Hanna (Ashley Benson) made great strides in episode 2, the girls are still haunted by the fact that their tormentor is on the loose. It doesn’t help that they don’t believe “all the information they’ve been told.” With nowhere else to turn, the Liars will try to “unravel the identity” of their kidnapper on their own.

The promo video teases that the Liars will look to Alison (Sasha Pieterse) and Jason (Drew Van Acker) for answers about “Charles DiLaurentis.” And although their father wasn’t helpful, Jason might have some information that could shed new light on the mysterious person.

“Jason always said that something was missing from this family,” Alison tells the girls in the promo. Meanwhile, a clip from the upcoming episode shows some baby photos missing from a family album. Could Charles really be Jason's twin brother?

Season 6, episode 3 of “Pretty Little Liars” will air on ABC Family on Tuesday, June 16 at 8 p.m. EDT. Who do you think Charles is? Tweet your thoughts to @AmandaTVScoop.