Once Upon a Time Mega Buzz: Who is Lady Tremaine's Prisoner?

Welcome to Mega Buzz, your go-to place for the latest and greatest spoilers on your favorite TV shows. We know you have questions, and we have answers! If you're craving scoop on something in particular, e-mail us your question at mega_scoop@tvguide.com or drop us a line at Twitter.com/TVGuide. You can also catch up on all the latest Mega Buzz right here!

Once Upon a Time threw us a curveball in Season 7 by revealing that Lady Tremaine (Gabrielle Anwar) has a mysterious witch locked away in Hyperion Heights. The real kicker is, unlike everyone else, she's totally awake instead of under the curse.

But who is this witch and what's she got to do with Tremaine?

"Very soon you'll learn who she is and that she's got connections to multiple characters," executive producer Adam Horowitz says.

"I would say that the majority of our audience has guessed it," Eddy Kitsis adds.

The most common guess from fans on social media is the witch is Mother Gothel, who you might remember as the villain of Rapunzel's story. She kidnapped Rapunzel as a child and locked her in a tower in order to use her hair for eternal youth. Some fans also speculated that this witch was the one who locked Hook's (Colin O'Donoghue) daughter away in the prison he mentioned earlier in the season.

"The one thing I can say is don't let her out," Kitsis teases. "She makes Lady Tremaine look like young Snow White."

Once Upon a Time airs Fridays at 8/7c on ABC.