We're only two episodes into the new season of Pretty Little Liars , and already the characters are behaving as shadily as ever. Alison DiLaurentis — the original "pretty little liar" — has officially returned from her two-year hideaway, and she's throwing the entire town for a loop. It's not surprising that everyone is Rosewood is acting weird following Alison's "resurrection," but the person acting beyond strange is Ali and Spencer's brother, Jason. Something is definitely going on with the guy, and I have a theory that may explain his odd behavior.

Jason's odd behavior started long before Ali announced her arrival in Rosewood, which is suspicious on its own. After Jason told everyone that he was leaving for "rehab" months ago, Spencer discovered that the alleged rehab center where he was staying didn't even exist anymore. (Why you would lie about going to a specific rehab place and not even remember to Google it, I have no idea.) That means that, for those few months, Jason was doing something shady — and it had nothing to do with getting clean and sober.

Now that he's back in Rosewood, Jason is acting highly suspicious. He didn't seem particularly shocked that Ali was back, making the liars suspect that Jason knew she was alive all along. Then there's his fierce protection over his mother — almost as if the two of them share a major secret. Given the late Mrs. DiLaurentis' shady nature (she did bury her daughter alive) that's not exactly a good sign.

Though the liars have started to suspect that it was Jason who knocked out Ali with that rock two years ago, I have a feeling that's not Jason's secret. It's way too obvious. Of course Mrs. DiLaurentis would want to protect Jason, but there's no way we've waited four seasons to find out that Ali's so-called "killer" was Jason — the person Mrs. DiLaurentis covered for would have to be someone we wouldn't immediately suspect. Jason reeks of a red herring, but that doesn't mean that he isn't covering for someone who did try to kill his sister.

In order to consider what we know about Jason, we first need to look at what Mrs. DiLaurentis knew. Mrs. D isn't exactly around to fill in the gaps, but luckily, her email — which Hanna peeked at — did give us a clue as to who she was communicating with just prior to her death. In her drafts folder, Mrs. D had an email that stated "I can't protect you anymore." The girls immediately jumped to Jason as the person Mrs. D couldn't protect but, as I said, that's just way too easy. What if Mrs. D and Jason were protecting the same person — Jason's secret twin?

The twin theory was first introduced in the Pretty Little Liars book series, and I wouldn't be at all surprised to see the show implement a twin in another way. In fact, it seems pretty likely: Last February, PLL actress and Jenna portrayer Tammin Sursok told The Daily Edition a twin sister will pop up on the series. We've written about how there could be a secret sibling on Pretty Little Liars , and given Jason's recent behavior, I'm starting to believe that this secret sibling could be Jason's twin sister... and that her intentions are anything but good.

There are a few clues that point to Jason's secret twin outside of the "secret sibling" theory in itself. For one thing, Jason seems to have strengthened his loyalty to his mother this past season, after years of mistrust surrounding his family. Mrs. DiLaurentis could have finally told Jason the truth about Ali's death by telling Jason that it was his twin who tried to hurt Ali — and that they needed to protect Jason's twin at any cost. Jason and Ali have always had a rocky relationship, but perhaps Jason would feel obligated to a twin whom he was never allowed to know — she would, after all, be the closest biological sibling he has. That might matter to someone like Jason, who really hasn't been able to fully trust anyone in his family.

But while Jason might think that he's protecting his sibling from prison, what if he's also inadvertently protecting Ultimate A? Let's be honest — there's no way that Shana is the only A on the block. My theory? That whoever Mrs. DiLaurentis and Jason were protecting — this secret twin of Jason's — is also the Ultimate A... and that both Mrs. D and Jason were in the dark about it. We know that Mrs. DiLaurentis suspected Spencer of being original A, possibly because of the secrets that this A knew about the DiLaurentis family. Mrs. D told Ali that you can "never trust a Hastings" — which is exactly what Jason's twin would be: A Hastings. Could that be a clue that the Ultimate A is a Hastings, AKA Jason's twin sister?

There's definitely a chance that Jason could be protecting someone very close to both the Hastings and DiLaurentis family... and the person responsible for setting the A plan in motion.

Be careful, Jason. Wouldn't want you to end up in a shallow grave, too.

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