Credit: Eric McCandless/ABC Television Group © 2012 Disney Photo: Melissa Hastings on the Pretty Little Liars Season 2 FinalePretty

One of the cleverest plot devices Pretty Little Liars uses is the sharing of secondhand information to create questionable truths. For instance, in the Season 4 premiere, Mona claims that Wilden and Melissa (Torrey DeVitto) were both the Queen of Hearts that caused so much trouble on the Halloween train. She has a video to prove it, but uh-oh! “A” erases the video from Mona’s computer before the Liars can verify for themselves that Melissa was in fact the second masked villain. Do we believe Mona that Melissa was really on the train that Halloween?

Yes, Melissa was definitely on that train

Though we may not have actually seen Melissa’s face to prove she was one of the Queens of Hearts, there is plenty of evidence to suggest it’s true. First, there is the “B” Team connection between Melissa and Wilden. In the Season 3,finale, we see that both of them have a connection to Jenna and Shana the other members of the “B” Team. It follows that they were also working together as the Queens of Hearts.

Secondly, we have seen Melissa don a costume in the name of nefarious plotting before. She admits to being the Black Swan the night of the masquerade ball, but tells Spence that she was blackmailed into the costume and the trickery by “A.” Given recent evidence, we’re not so sure. Could Melissa have been on “B” Team business both the night of the masquerade ball as the Black Swan and the night of the Halloween train as the Queen of Hearts?

No, Mona is setting Melissa up

On the other hand, since when have we ever been able to trust Mona? The girl is a pathological liar, and we have enough confidence in her computer skills to believe she staged that convenient erasure of the video showing Wilden and the second Queen of Hearts. Melissa may be dubious, but we’re not sure if we believe she would be willing to kill Aria, one of her sister’s best friends. We also know she was close to Garrett, who also ended up dead and in the teetering crate with Aria.

Another piece of evidence that doesn’t quite match up is the fact that Aria stabbed presumably one of the Queens of Hearts when they were trying to push her off of the train. We didn’t see Melissa to know that she wasn’t the victim, but it is implied in a later episode that Jason was injured in a similar way. If Wilden is one of the Queen of Hearts and Jason is the other, that leaves less room for Melissa because three people dressed up as the same thing on Halloween? Tacky.

Do you think Melissa was on the Halloween train that night? Or is Mona setting her up? Share your theories in the comments below!

Catch the next episode of Pretty Little Liars on Tuesday, July 2, 2013 at 8 p.m. ET/PT on ABC Family.