Pretty Little Liars : Who killed Charlotte?

Spoiler alert: This post contains spoilers for the June 20 episode of Pretty Little Liars!

Yet another Rosewood mystery has been solved.

In Pretty Little Liars' penultimate episode, the show revealed who killed Charlotte DiLaurentis, a mystery that was put into place after Charlotte was pushed out of the bell tower in the Season 6B premiere—just after finally being released from the hospital after five years.

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Turns out Charlotte's killer was none other than Mona Vanderwaal—and she seems to have had a good reason. The night Charlotte was released, Mona met her at the bell tower and confessed that she'd been watching Charlotte over the past five years though she wasn't allowed—per Ali—to actually visit her at the hospital. Apparently, Charlotte had been lying to her doctors and lawyers to make them think she was better, but she planned to return to her old tricks and continue torturing the Liars after she got out.

"Now I'm back, and everything that happened before? That's gonna feel like a picnic," Charlotte taunted.

Mona planned to push her out the window to make it look like a suicide but at the last minute decided to let Charlotte live. That only made Charlotte come at her stronger. "I knew you didn't have the guts," she said. Charlotte attacked Mona and they fought, then Mona gained the upper hand and pushed her against a wall… jamming Charlotte's head right into an exposed piece of metal, killing her.

Thus, Mona couldn't make it look like a suicide… but at least the police never found the murder weapon.

Stay tuned for our full recap—but in the meantime, what did you think of the reveal? Let's discuss in the comments.