Mary Drake's plans are as inscrutable as her Pretty Little Liars past.

Jessica DiLaurentis' (Andrea Parker) twin is up to no good - that we know for sure. A 23-year absence has turned the former Radley patient into an enigma, one whose end game and allies remain a mystery. Even her partnership with Elliott (Huw Collins) is a fluid monster.

"We're going to have a lot of fun learning about her relationship with Elliott, how they met, their relationship with Charlotte, are Elliott and Mary really on the same page or do they have different goals and what exactly are those goals," executive producer Charlie Craig told Entertainment Weekly. "That's going to be a very interesting story to tell, and also, what Mary's ties are to the girls, to this town. We know a little bit about her history and we're going to learn a lot more."

Mary "rescued" Hanna (Ashley Benson) at the end of the season 7 premiere, and her choice could help widen the growing wedge between her and Ali's (Sasha Pieterse) nefarious husband.

"They have an agenda, but there is also a division developing between them, which gives us two different people to think and worry about," Craig told The Hollywood Reporter. "It is possible that maybe together they are 'A.D.' or working for 'A.D.' which is the same as Uber 'A' this season, but there will be some divisions between them."

So, what is Mary's next move? Check out the episode summary for this Tuesday's "Bedlam" to find out more:

"With the fallout of Hanna's abduction still weighing heavily on the PLLs, the Liars begin to grow suspicious of Elliott Rollins as Ali's condition worsens. Tensions rise between Liam, Aria and Ezra as they work on the book together. Spencer and Caleb are on edge, as neither of them want to talk about the awkward elephant in the room," Freeform teased. "Meanwhile, Emily receives a disturbing phone call and tries to find a way to see Ali."

Pretty Little Liars airs Tuesdays at 8 p.m. ET on Freeform.