Our world was turned upside down on Pretty Little Liars Season 3, Episode 12: “The Lady Killer,” when we learned Toby (Keegan Allen) is on the "A" team.

While we know the truth, the Liars don't, and since the audience isn't able to reach through the TV and drop them a note, they're going to be in the dark for a bit. However, we do know his secret won't be kept forever.

Read spoilers at your own risk! For more on Wetpaint Entertainment's philosophy on spoilers, click here.

On Season 3, Episode 16: "Misery Loves Company," one of the Liars will learn the truth, and according to showrunner Marlene King, "the fallout will be huge."

But which Little Liar will be the first to find out? We're going to speculate about why each Liar might be the first to know, and think about whether or not we want them to have that pivotal role. We've already looked at why Emily (Shay Mitchell) and Hanna (Ashley Benson) might be the unlucky one (here and here), and now we're going to break down why it could be Aria (Lucy Hale) instead — and whether that's a good idea.

Why she might be the first to know: Aria is supposed to suffer in the winter season. A lot. And what could cause more suffering than finding out the truth about Toby? First, there would be her internal angst. Should she tell Spencer (Troian Bellisario)? The other Liars? And if the "A" team found out she knew the truth, chances are they'd go to extreme measures to keep her quiet. 

Why this would be interesting: One of our biggest beefs with this show is that Aria is often sidelined from the main plot. There have been many times over the course of the series when she's been more focused on drama with her family and/or Ezra (Ian Harding) than on what was happening with "A". This would ensure that she's at the center of the action. And we'd be very interested to see how she'd handle this situation.

Why we don't want her to be. As much as we want to see Aria caught up in the midst of the main plot, the fact is that she doesn't have much personal attachment to Toby. Her finding out would involve less of an emotional punch than if it were Spencer or Emily.

What do you think: Do you want Aria to be the first to find out?

Find more Pretty Little Liars spoilers here.

Don’t miss the next new episode of PLL, the Halloween special, on Tuesday, October 23 at 8 p.m. ET/PT on ABC Family.

Rebecca Martin is an editor at Wetpaint Entertainment. Follow her on Twitter @BeccaMartin47.

Want more Pretty Little Liars? Like us on Facebook and Follow us on Twitter and Tumblr.