Jessy Schram

Once Upon a Time there was an unhappy girl who lost her father and was forced to live with her evil-stepmother and two evil step-sisters until a missing glass slipper set her free.

This Sunday's episode of Once will introduce Cinderella (Falling Skies' Jessy Schram). In the original Cinderella story, she was orphaned and left in her step-mother's care, where she was expected to wait upon her family until her fairy godmother turned her life upside down by turning her into a beautiful princess so she could attend the ball where she'd meet her own Prince Charming. After running out at the stroke of midnight, the prince searched for her with the help of a glass slipper and the pair lived happily ever after.

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In the world of Once, however, Cinderella doesn't have the same luck. "You already know Cinderella is very kind and very sweet, but she's in the unfortunate situation of having lost someone in her life," Schram tells TVGuide.com. "The Cinderella that you'll see is a portrayal of someone that's desperate to get out of the situation that she's in. Because of that, some bad decisions are made and she's stuck in even more unfortunate circumstances. Though she's matured through her upbringing and being alone most of the time, she's naïve to the outer world."

A friend of Snow White (Ginnifer Goodwin) in the fairytale world, Cinderella's Storybrooke counterpart, Ashley, will come to bond with Emma (Jennifer Morrison). In Storybrooke, Ashley has been perpetually pregnant until Emma's arrival kick-started the clock in the town's square. "Ashley's trying to get away from some bad decisions, and Mr. Gold [Robert Carlyle] is tied to that because everyone makes a deal with him. Because of her pregnancy at such a young age, Emma sees a lot of herself in Ashley and she helps her and guides her; Ashley grows some balls because of Emma coming to town."

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Ashley's issues with Mr. Gold are not just limited to Storybrooke, as Cinderella finds herself at odds with his counterpart, Rumplestiltskin, in the fairytale world. "Mr. Gold makes deals, Rumplestiltskin makes deals," Schram teases. "How Cinderella gets to the ball isn't necessarily how you might've remembered it."

How does she get to the ball? That will be answered in Sunday's episode of Once at 8/7c on ABC. Until then, hit the comments with your theories.