Storybrooke residents are finally prepared to do away with the cruel Snow Queen and bid adieu to Elsa, as well as her sister Anna, in the 'Once Upon a Time' mid-season four finale. The episode airs on Sunday, Dec. 14, via ABC, and after that, the series will go on hiatus until March 10.

In a recent interview with Entertainment Weekly, 'Once Upon a Time' executive producers Adam Horowitz and Edward Kitsis revealed some details about the residents of the mystical village of Storybrooke.

Apparently, they will start believing that they'll return to their normal lives once the sisters return to Arendelle, and they get rid of the Snow Queen, but little do they realize that the other evil forces are going to emerge

The duo revealed that in the upcoming episode, viewers will see Cruella De Vil of '101 Dalmatians', Ursuala of 'The Little Mermaid', and Maleficent of 'Sleeping Beauty' collaborating to create chaos.

Teasing about the events in 'Once Upon A Time' Season 4 Episode 12, Kitsis said, "We've always said evil is not born, it's made. One of the things we're so excited about with these three villains is showing their origin stories. We've never seen the origin stories with Maleficent, Ursula, or Cruella, so we're excited about that."

Replying to a question about the reason for choosing the new characters introduced in the series, he revealed, "We always wanted to bring Maleficent back. We thought, 'What is the greatest team of evil we could gather to go up against?' Ursula we teased in the Ariel episode last year, and then Cruella, for a while, we just always wanted to bring her on the show and couldn't figure out how because in the movie, she was kind of [1950s]. You always want to put your twist on it. For us, Cruella just fit into this trio of terror."

According to EW, the plot of the upcoming 'Once Upon a Time' episode supposedly focuses on the mission of the villains' quests to find their own story of "happy endings." However, this may lead them into a clash with Emma as well as the other heroes of Storybrooke.

Horowitz and Kitsis also revealed that Victoria Smurfit will play the role of Cruella de Vil, Merrin Dungey will portray Ursula ,and Kristin Van Straten will appear as Maleficent on the show.