On Pretty Little Liars Season 4 Season 4, Episode 5: “Gamma Zeta Die,” we learnt about the mysterious Carla Grunwald, the intimidating sorority house mother who may have been linked to the secret room Ali was calling. Who is this woman?

We've gathered everything we learned about her from the episode, as well as what we've heard about her from sneak peeks and spoilers right here.

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She was a former house mother. She's from before the time of the sorority sister who was showing Emily around, and "legend has it that she was fired."

She was not loved. "Apparently you couldn't get anything past that bitch," the sorority sister told Em. It was like she knew you wanted to sneak out before you even did it.

She would disappear and reappear at will. Spencer apparently did some more asking around, and in this sneak peek of Episode 6, she reveals that she learned that Grunwald would "disappear for hours" and then "poof, she would reappear as if she'd never left the house." Hmmm ... sounds like she might have been in that secret room.

"A" is interested in her. "A" looked at a picture of her in the tag to Episode 5.

She's linked to Ravenswood. Surprise, surprise: This character is linked to Ravenswood, the town that will serve as the setting for the new PLL spin-off. According to this spoiler, she will be in next week's Episode 6 (indeed, she's probably why Spencer and Toby take a trip there), and she's described as "no-nonsense" and "stubborn."

Do you think Ms. Grunwald is linked to Ali? Share your theories in the comments below!

Find more Pretty Little Liars spoilers here.

Catch the next episode of Pretty Little Liars on Tuesday, July 16, 2013 at 8 p.m. ET/PT on ABC Family.