I was rewatching 5x12 for a thousandth time because I liked it very much (one of the best episodes in my opinion) and I think one of the most interesting parts is Alison’s lie detector test.
Especially the last thing she says:
And then towards the ending of the episode, Mona calls Aria to tell what she found out.
She tells Aria that Alison knew about the affair and she was jealous of Bethany and wanted her dead, so she lured her to Rosewood, and then, as we know, Bethany died there.
That doesn’t sound like Alison had nothing to do with Bethany’s murder, does it? If Alison really did lure her to Rosewood then she would be the reason Bethany died. Note that it doesn’t necessarily have to mean she murdered her, it simply means she somewhat caused her to get murdered. But she claims she had nothing to do with her murder which must be the truth since she had a polygraph on her.
So let’s say Alison really didn’t have anything to do with Bethany’s murder but Mona is also right about what she found out (I mean, she has to be, because to quote the liars “She is Mona”). These two things don’t add up but there is a possible explanation:
What if Bethany doesn’t really know Alison but thinks Cece is Alison instead? In 4x10 we were given a flashback about how Cece went to Radley and claimed to be Alison and wore her clothes (similar to how they were dressed the night Alison ‘died’).
If Cece visited Bethany when she was there, Bethany would believe Cece is Alison, assuming she never saw Alison before. And I do believe that’s the first time Bethany saw ‘Alison’ because the staff at Radley also thought Cece is Alison, which means Alison herself never visited Radley before.
We also learn from that flashback Cece and Alison liked to play ‘games’ together. While what Cece did must have been… ‘fun’ it was also quite pointless as it only made Mrs. Dilaurentis mad. There must be another reason for Cece to go to Radley and pretend she is Alison, right? So what if Alison asked Cece to do such a thing? This might been another one of their games. Maybe Alison didn’t want Bethany to know who she was.
So what I’m saying is: Maybe Alison didn’t lure Bethany to Rosewood but Cece did and she wanted her dead for some reason. There is no way to tell what the reason would be since we don’t know much about Cece.
Or maybe I’m just overthinking things. Nonetheless, it’s still something to think about.