'Pretty Little Liars' Season 5 Spoilers: Does Jason Have a Twin Sister?

The theory of one of the "Pretty Little Liars" characters having a twin gained traction recently after Tammin Sursok, who plays Jenna Marshall in the ABC Family's thriller drama, hinted at the twin sister mystery during an interview.

"Someone has a twin sister — I can't give too much away," Sursok told The Daily Edition, and added that the mystery regarding most of the characters is going to deepen in Season 5, Celeb Dirty Laundry reported.

Dropping yet another bombshell, she also revealed that A is not dead, as the Liars believe.

"There's a lot of bad things that happen. We find out who 'A' is, and then it's not really 'A' and then someone has a twin sister — I can't give too much away," Sursok said.

Fans of the book series that "Pretty Little Liars" is based on have for long expected Alison DiLaurentis's twin Courtney to make an appearance in the series. But because the television drama is taking a different route than the books, many suspect that it might be Jason who will be shown as having a twin.

Jason is the love child of Mrs. DiLaurentis and Mr Hastings, and its speculated that the twin might be the one who hit Alison with a rock. This might also explain why Mrs. DiLaurentis would prevent authorities from finding who the culprit is.

Also, the existence of Jason having a twin sister might be the secret that Melissa and Mr Hastings have been keeping from Spencer, according to Celeb Dirty Laundry.

A promo of episode four, entitled "Thrown from the Ride", shows Spencer pestering her mother to reveal what Melissa and her dad are hiding. However, Mrs. Hastings appears to be in no mood for Spencer's questions.

Another clip from the upcoming episode shows Alison struggling to get on with life after faking her death. She attempts to get in touch with Emily, and the clip shows her typing a text for her pal.

"Can you call me back please? – A," writes Alison before deciding to write out her full name.

Besides Alison, Aria too will be finding it hard to resume her old life as she is struggling with the guilt of murdering Shana. She will be suffering from depression after the events of New York, and will look to an "unlikely source" for comfort, official synopsis of the episode stated.

To make matters worse, Alison will try to take on the leadership of the group, which does not go down well with the others, who are now feeling the pressure of "being under the microscope."

Episode 4 of "Pretty Little Liars" will air on ABC Family on Tuesday at 8 p.m. EDT.