Talk:The First Secret/@comment-24.108.97.164-20131129221540

Alison does have a twin, Courtney. This is the whole plot of the whole series, so if you want spoilers, read on.

Courtney is mentally insane and has been impersonating Alison for as long as the liars have been friends with "Alison." The Alison they know and love is really her mentally insane twin, Courtney. Courtney is very evil to the real Alison and nobody can tell the difference between the two, so her parents accidentally sent the real Alison to a mental asylum instead of Courtney, who is Alison. That's why 'Alison' is such a biatch to her friends, because she's mentally insane. So when Alison (presumed to be Courtney) comes back from the mental asylum, furious that her sister is impersonating her, she murders her sister. This is why everyone thinks Alison was murdered. Really, Alison is alive, but Courtney was murdered. That's why there are two girls that look just like Alison in the photo collage on Alison's wall. After she murdered her sister, she fled Rosewood. I'm not sure how A comes into the picture, though. But everybody knows Courtney as Alison, and no one else knows that she has a twin sister.