Though much is still unknown about the night of Alison’s (Sasha Pieterse) disappearance on Pretty Little Liars, one truth has become unsettlingly clear: Ali was buried alive. Though she was eventually pulled from the ground by Mrs. Grunwald, that doesn’t keep us from asking the question: who put her there? PLL showrunner Marlene King has said we will discover the identity of the gravedigger in Season 4. In the meantime, we speculate below.

Jenna

The day Alison was buried alive, Ali visits Jenna at the Rosewood hospital to scare into keeping the secret of “the Jenna thing.” Ali tells Jenna that, if she ever returns to Rosewood, she will bury her. Alison was referring to the videos she had of Jenna forcing Toby into a sexual relationship, but we wonder if Jenna took the literal meaning of the threat and sought revenge on Ali. It seems somewhat unlikely given that Jenna was blind at the time, but the wording of the threat gives us pause and Jenna has faked blindness before.

Ian

We’re still confused about Ian’s role in Ali’s disappearance. In Season 1, he was the Liars chief suspect and even seemed to admit to killing Ali in the Season 1 finale right before he tried to kill Spencer. We know Ali and Ian were involved in a relationship, and that Ali had N.A.T. Club tapes that all of its members wanted back. Maybe Ian really did think he killed Ali when he buried her alive. After all, she could have easily died if Mrs. G. hadn’t come along.

Byron

One of the problems with figuring out the details of Ali’s disappearance is that seemingly every person in Rosewood had some reason for wanting her dead. Byron Montgomery (aka Aria’s dad) was being blackmailed by Ali, who knew Byron was cheating on Ella with Meredith. They met the night of Ali’s disappearance and Byron told Ali that he wasn’t going to give her any more money, that he thought she wouldn’t really hurt the Montgomerys by revealing his secret. Their relationship seemed to end with that conversation, but did Ali push the blackmail further? And did Byron bury Ali to keep her quiet? He did take off to Iceland for a year following her disappearance.

Melissa and Cece

We believe Melissa is capable of nearly anything, especially when it comes to protecting herself and the people she loves. Melissa was pissed at Ali the night of her disappearance. She stormed into the DiLaurentis house looking for Ali. Later that night, Jason remembers seeing Melissa with Cece engaged in an important discussion. Cece is dressed in clothes similar to the ones Ali was wearing that night (a yellow tank top and skinny jeans), and Jason initially confuses Cece for his sister. Were Cece and Melissa enacting some sort of dastardly plan to punish Ali? Were they the ones who buried her alive?

Spencer

Speaking of Hastings, Spencer is another one we can’t help but add to the list of suspects. Ali was threatening to tell Melissa about the kiss Spencer shared with Ian. The two got into a fight the night of Ali’s disappearance, with Spence telling her BFF, “You are dead to me already.” (Oddly prophetic, at the time.) Ali was sleeping over Spencer’s house that night and, when Aria, Hanna, and Emily woke to find Ali gone, Spencer was gone, too. She soon wandered back into the sleepover, a vacant expression on her face and with the news that she couldn’t find Ali. In a fit of anger, did Spencer do something to her friend? Like bury her alive.  

Who do you think buried Ali alive? Share your theories in the comments below!

Catch the Pretty Little Liars Season 4 Halloween special on Tuesday, October 22, 2013 at 8 p.m. ET on ABC Family.

Credit: Celebified Photo: Pretty Little Liars Halloween Special "grave New World" Preview Photos: Ezra Lurks In The Shadows While The Girls Search For Ali!