If there's one thing we know about Pretty Little Liars, it's that we should expect the unexpected. The show loves to lead fans in the wrong direction, which means they have to think extra creatively to keep ahead of the writers. Fortunately, the Pretty Little Liars fandom is more than up to the task, which is why, each week, we like to delve into the wilds of Tumblr to highlight an interesting theory.

This week, we want to talk about a smart theory from Tumblr user Spencer's Barn: That Jason DiLaurentis (Drew Van Acker) is the one who attacked the girl in Ali's grave and Melissa Hastings (Torrey DeVitto) saw.

Why do we like this theory? Here are a couple of reasons:

It explains why Jason sometimes acts sketchy. We always struggle with the idea that Jason is on the "A" team or is the one that attacked Ali, since he seems to genuinely care about his sister and overall seems like a decent guy, not a crazy stalker. That said, it's hard to deny that he can be hella shady; perhaps this is his secret.

He was really messed up that night. We all know Jason was so drunk/high on the night of Ali's death that he barely remembers it. That makes it more likely that he might have attacked someone in a drunken stupor, and it means he wouldn't even need a good reason to attack the other girl. A little anger can get very magnified when you're that messed up; plus, it's possible that he accidently killed someone when he only meant to, say, scare them a little.

It would explain Melissa's reluctance to talk and Mr. Hastings’ reaction. Melissa seems hesitant to come forward with her story. If the person she saw attack the other girl was Jason, that makes sense they are bound together by all sorts of N.A.T. secrets, so she might be worried about what he could say about her. This would also explain why Mr. Hastings shut Melissa down when she did try to spill the truth. After all, Jason is his child.

What do you think of this theory — is it possible, or totally crazy? Sound off in the comments below.

Catch the next episode of Pretty Little Liars Season on Tuesday, June 24, 2014 at 8 p.m. ET on ABC Family.