So, who do we think is the most likely culprit at this point? This episode didn't give us a whole lot to go on, but here are four people we've got our eyes on.
Why she might be "A": We can never forget that Mona was the original "A", and it's possible she never really gave up the mantel entirely. She's one of the few characters on this show clearly capable of pulling the "A" game off, and the fact that she's once again organizing a large group against Ali adds to our suspicions.
Why she might not be "A": In the end, we think it's more likely that Mona is a rogue agent, working in her own best interests but not running the "A" game any more. We think she's more interesting that way.
Why she might be "A": Like Mona, Melissa is one of the few people smart enough to pull this whole thing off, and we still find the timing of her return to the States highly suspicious.
While she couldn't have been running around doing a lot of the "A" dirty work this week, we wouldn't put it past her to be coordinating it all from the Hastings home.
Why she might not be "A": Melissa seemed genuinely surprised by the news that Ali is alive, and truly freaked by whatever secret she confessed to her dad, which doesn't seem very "A"-like. Plus, while she could have been texting orders on the side, she was pretty busy this week, which makes that slightly harder to buy.
Why he might be "A": We're always suspicious of Wren, whose motive for being so involved with the Liars' lives has always been unclear. He wasn't on screen this week, but that's all the more reason to wonder about him. He could totally be running around NYC or Rosewood, doing dirty "A" work.
Why he might not be "A": While Wren has many suspicious connections to the Liars, Melissa, Radley, etc., we still don't really have a any idea what his motive would be if he is Big "A".
Why he might be "A": Peter Hastings is a scary man, as his scenes with Melissa reminded us this week. He'd do anything to protect his family's reputation, so if he thought Melissa or Spence was involved with Ali's disappearance — or if Ali had been threatening to expose the truth about Jason back in the day — we could see him going to extreme lengths to keep things covered up.
Why he might not be "A": It just seems insane for a grown man to spend time torturing teen girls. We don't trust Peter further than we can throw him, but we're also not convinced he'd go about dealing with his problems in the way "A" does.
Who do you think "A" is? Let us know in the comments below!
Catch the next episode of Pretty Little Liars Season on Tuesday, June 17, 2014 at 8 p.m. ET on ABC Family.