Credit: ABC Family

Big "A". Red Coat. The sicko in charge of it all. Whatever you want to call her (or possibly him), the Liars' greatest threat is still a mystery on Pretty Little Liars, which means every episode is a new piece of the puzzle. Who do we think "A" could be after Season 4, Episode 7: "Crash and Burn, Girl!" ? We've gathered our top suspects.

3. CeCe Drake

Why she might be Big "A": Beyond the general reasons we suspect her, Nigel singling her out as the blonde on the plane certainly makes her seem very guilty. It's very possible she was the one who was there the night of the fire.

Why she might not be Big “A”: As we've said before, we think Big "A" is going to be someone who has been part of the show since the beginning. Plus, we kind of think Nigel might have been lying to frame CeCe. There's no reason for us to trust what he said.

2. Jenna Marshall

Why she might be Big "A": Nigel clearly knew a lot about the night of the fire, and who is he associated with? Based on the sunglasses near the end of the episode, it would appear to be Jenna — which makes sense, since he also accompanied her to Wilden's funeral in the Season 4 premiere. We can definitely see Jenna as a mastermind with all sorts of minions (Nigel, Shana, etc.) doing her dirty work for her.

Why she might not be Big “A”: We definitely think Jenna is up to something, but while she could be Big "A", she is even more believable as an independent agent fighting her own battles.

1. Alison DiLaurentis

Why she might be Big "A": Ali is at the top of our list for all the reasons we've discussed before. Plus, it's possible Nigel isn't intentionally framing CeCe: We could totally see Ali using her former mentor's name when chartering a plane. Or maybe he's working for/with Ali as well as (or in conjunction with) Jenna.

Why she might not be Big “A”: As always, we have to acknowledge that she might actually be dead. So, that.

Of course, these aren't the only people we have our eyes on. In Rosewood, anything is possible.

Who do you think "A" is? Sound off in the comments below!

Catch the next episode of Pretty Little Liars on Tuesday, July 30, 2013 at 8 p.m. ET/PT on ABC Family.

Credit: YouTube Photo: Pretty Little Liars Season 4, Episode 8 Preview: "The Guilty Girl's Handbook" (VIDEO)