We Finally Know Who Killed Charlotte On 'Pretty Little Liars'

Charlotte's killer on Pretty Little Liars has finally been revealed, with one episode left.

And the story behind her killing was a lot more complicated than many thought, of course.

So make sure you're ready for spoilers, because here we go...

Mona killed Charlotte.

DAAAAAAAANG, right????

Finally, we have a legitimate answer.

So much of the final season has been hinged on this fact, as AD was apparently torturing the liars to figure out this information.

For a while there, the show was hinting that Mona herself was actually AD. But on this week's episode, it was made pretty clear (I hope?!) that Mona was not actually AD.

Instead, it appears, Mona was having a sort of psychotic break, reverting back to her high school days as she tried to figure out AD's game.

And it turns out Mona killed Charlotte for a helpful reason -- well, as helpful as killing someone can be.

Mona had a flashback in this week's episode, witnessed by Hanna, at the top of the church bell tower.

In the flashback, she was with Charlotte at the top of the tower. Mona had some flowers for her (if you remember, the police said Charlotte had flowers when she fell from the tower to her death).

Mona told Charlotte she had been watching her, carefully, when she was being held for five years. Mona saw that Charlotte was not actually reformed from her torturing days -- she still had that evilness bent towards the liars.

"Five years of making the doctors feel so clever with all the progress you were making. You played them all. The court, the lawyers, your own sister," Mona told Charlotte.

But, Mona said, Charlotte couldn't fool her.

Charlotte then started to taunt Mona.

She told Mona that she still sees her as a loser with the "pigtails and the pony sweater" like she was way back at the start of all this.

"None of you are really certain who you are," Charlotte told Mona. "I did that. I took that away from you. The same way everything was stolen from me."

Charlotte went on to tell Mona that she was going to come for the liars.

"Everything that happened before, that's going to feel like a picnic," Charlotte said.

So Mona picked up a screwdriver.

Charlotte kept taunting her, saying she didn't have the "guts" to do something.

Mona steps forward, pushing Charlotte towards the edge of the tower.

"Jump," Mona tells Charlotte. "Jump or I'll push you. I'm giving you more of a chance than you ever gave any of us."

Mona wasn't actually trying to kill Charlotte.

She was going to let her live, but then Charlotte starting fighting her. Mona fought back, eventually hitting Charlotte's head against an exposed pipe. That's what killed Charlotte.

So that was it. Mona killed Charlotte, but to protect the liars from being tortured again. Apparently she's not AD -- she just got dragged back in by the memories.

Now we've got that answered. Just 49 million questions left to go.