Previously on Pretty Little Liars, it was revealed that Mary Drake, who is the biological mother of Spencer Hastings, actually had two babies and had to give them up when she was in the Radley institution. Many fans believe that Spencer’s secret twin could be A.D., the major villain of the series. In an interview with Cosmopolitan, showrunner Marlene King said that A.D. is someone “we haven’t revealed yet.” Since we haven’t met Spencer’s twin yet, this could definitely be a possibility.
Another theory that piggy-backs off the twin theory is that Andrew Campbell is actually Spencer’s twin, since we haven’t heard from him in a while. He did appear to be quite involved in the past and we do know that he is adopted.
Something strange that happened this season was an encounter between “Spencer” and Ezra at the airport. In their quick conversation, Spencer asked Ezra to not tell the other girls that she was there and who she was talking to (Wren). It was very odd and felt a bit out of character. Could Spencer have an identical twin?
On a PLL theories forum board, a fan called “MrsWren” wrote about the scene, saying:
This scene last night: This spencer had no watch, was wearing un-Spencerlike clothes and acting in a way that Spencer wouldnt have. Atleast not at that moment: She just found out about The credit card used. No way she would let all of that rest, call Wren out of the blue and yap about Cece. Her focus wasn’t on Cece atm. It was on Mary, Rollins and her cop lover trying to get her in jail. Our Spencer would’ve focused on a way to get that bill if she was to do something.
The fan also wrote:
The intro. The girl in the casket is wearing the same dress as Spencer is wearing.
Tonight’s episode is the last one before the grand series finale and the official plot description reads:
The Liars gear up for a confrontation with A.D.; Spencer, Hanna and Caleb discover new information regarding Charlotte’s death; Mary Drake returns with a gift for Spencer and Alison.
Perhaps tonight we’ll find out who killed Charlotte …