Once Upon a Time viewers will learn how Peter Pan (Robbie Kay) became such a villain in upcoming episodes of season 3.

Once Upon a Time co-creator Adam Horowitz revealed to E!Online in a Tuesday report that viewers will learn the backstory of Pan in season 3. Pan's trusted fairy Tinker Bell (Rose McIver) will also be introduced in episode 3, Quite a Common Fairy.

"We try to have a spin on it that's a little different than what you expect, and also there's a connection to some of our characters that you've already met," Horowitz explained, discussing Peter Pan's backstory and his relationship with Tinker Bell.

"And as for the Darlings, they're so integral to the Peter Pan story," he continued. "We have not forgotten about them and there is a connection and a tie into what we're doing with them as well."

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ABC also sent out a detailed press release about Sunday's episode, titled Lost Girl. In the episode, Peter Pan will appear before Emma (Jennifer Morrison) and give her a map, which might help her figure out where her son Henry (Jared S. Gilmore) is being kept. However, the map is only made visible when Emma accepts who she is and where she came from.

There will also be a flashback to the Fairy Tale Land that was, featuring the Evil Queen (Lana Parrilla) giving Snow White (Ginnifer Goodwin) the option to live her life with Charming (Josh Dallas) in peace under the condition that she gives up her claim to the throne. Charming will try to convince Snow to not take the deal.

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Once Upon a Time will air Lost Girl on Sunday, Oct. 7 at 8 p.m. on ABC.

Watch a trailer for the episode here:

Tags: Once Upon A Time Once Upon A Time Season 3 Spoilers