This 'Pretty Little Liars' Theory About Spencer And AD Will Blow Your Mind

We're getting very close to the end of "Pretty Little Liars," and with only a couple of episodes left until the series finale at the end of June, the big question on every fan's mind is the same: Who is AD!?

Thankfully, one super convincing fan theory seems to have it all figured out.

The popular theory states that Spencer Hastings has a twin, and that twin is AD! It sounds crazy, but honestly, a lot of things that have happened in this show are crazy.

I know they already did the whole "secret twin reveal" thing recently with Mary Drake and Jessica DiLaurentis, but it really sounds like the "Pretty Little Liars" team is planning on doing it again with Spencer and AD, especially when you rewatch that supposed dream sequence from the Season 7 premiere.

In that scene, Hanna is being held hostage by AD and dreams Spencer is there to comfort here. But there are a few things off about dream-Spencer.

She seems to be very curious about Charlotte's killer (just like AD), and she even uses the name "AD," even though Hannah hasn't heard it yet, so it seems impossible that she could dream it.

Most striking is the fact that at the end of the scene, Hannah lays in Spencer's lap while she sings "Hush, Little Baby" to her. Later in the season, we see Mary Duke singing the same lullaby in the exact same position to Spencer!

With all that in mind, many fans are saying that the dream-Spencer wasn't a dream at all, but actually AD, who happens to be Spencer's twin.

There's also a bunch of other bits of evidence that support this theory. Like Mary Drake telling Spencer she and Melissa used to look like twins, and Tyler Blackburn (Caleb on the show) telling Us Weekly that we've only "kind of" met AD in the series to date.

You've never met them... You kind of have. When you see it, you'll understand what I'm saying.

Hmmm, that comment sure makes a lot more sense considering the Spencer-has-a-twin theory!  So don't be surprised when we finally discover who AD is, and she looks awfully familiar.

Citations: This Pretty Little Liars Scene Might Confirm the Most Popular Fan Theory (Teen Vogue)