The actress hit the books at the New York Public Library

By Michele Corriston
June 17, 2015 05:45 PM
Jack Rowand/ABC

Emma Swan’s gone evil.

The May finale of Once Upon a Time saw Storybrooke’s heroine sacrifice herself to the darkness. So what does season 5 hold for the bounty hunter/princess by birth? Star Jennifer Morrison says she and showrunners Edward Kitsis and Adam Horowitz are “creating a villain that has never existed” – with a little help from fairy tales of yore.

Morrison, 36, visited the New York Public Library for inspiration on Emma’s wicked transformation.

“In order to build Dark Emma, I’ve been doing a bunch of research there with some of their mythology books and old fairy tale books and just looking back through the history of swans and the etymology of ‘Swan,’ ” she tells PEOPLE.

“I was given the opportunity to go to the rare books department, and they showed me some of the most incredible first editions of old fairy tale compilations that were just stunning,” she says. “There were some stories in there that I’d never heard of, so I have yet to read them. I have a list of them that I’m working my way through now!”

The actress – who was in Washington, D.C., Tuesday to speak to young women at the ANNpower Vital Voices Leadership Forum – says she’s “eternally grateful” to the library’s curators. She’s also thankful to work on a series with such rich opportunities for growth.

“Villains are fun to play as an actor, but no matter what, it’s also just fun to have something new,” she explains. “It’s so rare to go into season 5 of a show and feel like a character is evolving and changing at such a drastic pace that I really get stretched and challenged on a daily basis.”

TVLine has reported that ABC is trying to cast Merlin, King Arthur and Guinevere. So … are the characters headed to Camelot?

“We’re going to be going into another land, as we usually do,” Morrison teases. “Emma is going to be in a place in her life that she has never been.

“She spent her whole life working so hard to overcome the hardships that she endured and to try to be the best version of herself and try to be strong and, ultimately, in the last few years, to try to be the savior that she is supposed to be stated to be,” she adds.

“And now she’s in a position where she is free of all of that and is facing all of the potential darkness that she has tried to avoid. So we will see what that means for her, and we’ll see how she grows and changes because of that,” she says. “We’re also going to see everyone in her life fighting to try to get her out of that place and help her overcome it.”

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Season 5 of OUAT premieres Sept. 27 on ABC.