Mona's presence has been scarce during Pretty Little Liars Season 6, but she sure looks like she knows how to work that computer like a pro. I'm intrigued to find out what the hell it controls.
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Considering we know Ali's already met Charles and knows his identity, this might spell the reveal of Black Swan or Red Coat. The look on the gals faces are a picture, right? They look shocked to the core.
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The gals might look like they are in a Syfy show, but it's clear they are in search of answers. Anyone else willing to bet that this is the vault that is in the building Rhys works in? Either that or A has taken them in a time machine into the future. Also, could Mona be the person in red we saw chasing Ali last week? It would make A LOT of sense since she was nowhere to be seen.
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This is the picture that might prove that the liars are there for Mona, rather than Lesli. She knows something and based on her acting normal, this could be her new lair and it would be a perfect cover up.
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Mona does not look impressed. Throughout these stills from the episode, she is the only one who has remained calm and that raises our suspicions that she is back to being the master manipulator. Did she ever have a break?!
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Mona has a Radley Sanitarium case file, but could it be Lesli's? You can bet your bottom dollar it is! It may seem like Mona has come to her senses, but don't rule out the possibility that she has manipulated the contents of the file.
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It sure looks like Mona is back to just popping up in random places. It remains to be seen whether she is on team Lesli, or team liars. Either way, look for some choice words thrown her way from the liars.
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It looks like those pleas for freedom didn't work and the liars aren't getting back into the dollhouse, so they are spending the night in the yard with their pretty, mucky dresses and each other. I'm sure their conversation will be riveting.
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Pretty Little Liars Quotes

Lord help the mister who comes between me and my sister.

Cece

You think the truth is this big shiny disco ball of purity then go ahead and try it. See what it gets you. Telling the truth to the wrong person at the wrong time is how I ended up where I did. Take it from me you're always better off with a really good lie.

Alison