Only on "Once Upon a Time" could a typical episode include a mysterious disappearance, the origins of one of the infamous seven dwarfs and the presence of magical fairy dust but that's what viewers will see on Sunday's episode of the freshman ABC series. What happened to the missing Kathryn Nolan (Anastasia Griffith) and was foul play involved? How did dwarf Grumpy (Lee Arenberg) become so, well, grumpy? How does fairy dust (at the hand of guest Amy Acker) figure into it all? While this episode will more than likely answer some questions, expect more to be raised that will lead us through the rest of season one.

Co-Creators Edward Kitsis and Adam Horowitz, the masterminds behind the fairy-tale-centric series, recently opened up the Burbank writers' room of "Once" to a group of journalists (including our Jim Halterman) to talk about the evolution of the series, the connection to their previous series "Lost" and some of the juicy upcoming guest stars. Although the several dry erase boards in the room were covered so storyline secrets would not be spoiled, the co-creators were as forthcoming as they could be about upcoming adventures that will unfold in the coming weeks.

At the core of the series is the romance between saintly Mary Margaret (Ginnifer Goodwin) and dashing David Nolan (Josh Dallas), who, in reality, are Snow White and Prince Charming. Even though their memories have been erased by the Evil Queen/Regina (Lana Parrilla) and complications (and a little curse) keep the destined twosome apart, the writers do have a definite plan for them. "We are building to something this season with them that we're excited to share with you... just not today," said Kitsis. "There is a plan and there is a definite buildup we're trying to do and we hope people enjoy where we take them."

Horowitz also said that even though Mary Margaret and David cross paths often in Storybrooke and, at this point, cannot be together, it's clear that "their love is so strong it keeps pulling them together no matter how hard we try to keep them apart. But, of course, the curse [on Storybrooke] has to keep them apart."

Mary Margaret and David will more than likely come across more surprises and twists in their story since "Once" established early on that shocks in the storytelling is part of the master plan. That first big jolt was the surprising death of Sheriff Graham (Jamie Dornan), who was just embarking on a possible romance with Emma (Jennifer Morrison) when he was killed by Regina. Is there a chance, thought, that we might see the handsome Sheriff (or Dornan) again on the show since he did have a certain level of popularity. "To be quite honest with you," Horowitz said, "I hope so. We would like to have him back. Sometimes it is a scheduling thing that is beyond our control. Right now we are trying to move heaven and earth to hopefully make it happen, but I can't promise you." He added that he wasn't surprised that Dornan became a fan favorite. "You want your audience to be attached to characters and to see people really feel for him and really feel that loss... as painful as that is, that's what we were going for so that was gratifying."

While we wait to see if Dornan returns, viewers can turn their attention to the mysterious August W. Booth, played by Eion Bailey. Presumed good at this point, August was seen in the last episode repairing the very important fairy tale book that belongs to Henry (Jared Gilmore) and tells the story of our fairy tale characters. With the book now back in Henry's hands, much to the inevitable chagrin of Regina, what happens moving forward? Horowitz explained, carefully, "I'd say what we saw August doing in that episode, with putting the pages in the book, is kind of the first step in peeling back the onion on who this guy is and what his agenda in Storybrooke is." He added later that "August's goal in Storybrooke is one that is going to be revealed very clearly pretty shortly. It's a very specific goal."

Kitsis and Horowitz did reveal that we'll be seeing more of Belle (from Beauty And The Beast and played by "Lost" alum Emilie de Ravin) very soon - in this week's episode, as a matter of fact. Last seen imprisoned, Kitsis revealed that "she's got a nice little scene in Episode 14. She's sitting up there with the person who loves her, not realizing it. And that would be someone I would not want to piss off." The creators' affection for Ravin more than likely had a hand in bringing her back so soon. Horowitz gushed, "We love Emilie so much. We love what she's done with the character [of Belle] and we are excited to show you some more with her. And there's more this season." Kitsis confirmed that the actress would be back for more episodes closer to the end of the first season.

With so much on the canvas for the current cast of characters, there are plenty of new characters yet to come, as well. For example, the Mad Hatter (played by Sebastian Sand) will appear in an "Alice In Wonderland" themed episode (set to air March 25th) and Academy Award nominee Barbara Hershey is set to appear in the April 1st episode as the mother of Regina. Can fans expect us to sympathize with the evil Mayor once we learn who raised her? "It's more about understanding why characters do things," Horowitz said. "And it is one of the themes that we explore in the show... which is that to us evil isn't born, it's made... and kind of really getting into why Regina is the way she is and also why the mother is the way she is." He added that "that relationship will hopefully allow the audience to understand the characters on a deeper level." And assuming the show is renewed for a second season, Hershey has reportedly already signed on for a three-episode arc in season two.

An interview with Kitsis and Horowitz is almost impossible without a "Lost"-centric question coming into the mix. While some references to their previous show have been slipped into "Once," Kitsis explained that a lot of possible similarities are merely part of the work he does with Horowitz. "I feel like we're the writers we are," he said. "So we're going to tell stories the way we do. Like the storytelling we've done informs the storytelling we've done now... we don't ever want to repeat ourselves, but we do feel like we've been trying to grow as storytellers through our entire career, and 'Lost' was very formative for us. But by virtue of doing this show, which is its own thing, its own characters, its own world, we're trying to tell stories unique to that. And we have influences from a lot of places."

Asked about the working process they have together, the writers were more than happy to breakdown how their partnership has been so creatively successful. "I think one of the reasons we've worked together for so long is we have very similar sensibilities," said Horowitz, "and we just kind of get really excited about the same kind of ideas." Kitsis added, "The thing we loved most when we wrote for 'Lost' was that usually when you're on a TV show... if you're on a doctor show, it's the doctor show. If you're on a cop show, it's the cop show. But what was great about 'Lost' was it was the everything-show. We could write a cop story one week, and a Hurley lottery story the next week, and a rock star for Charlie the next week. And so that's what we loved about this idea was that we literally could write different tones and different things all together, and that's kind of what it is."

Finally, all this talk about the first season, of course, brought up questions about season two. While "Once" has not officially been renewed by ABC yet, it does seem to be a likely possibility due to strong ratings and a solid fan base. Have Kitsis and Horowitz thought about life beyond this current season? "We have big ideas about the show and where we would like to take it," Horowitz revealed. "But right now we're really focusing on the season we have, and finishing it out." Kitsis added, "We think we have some really unexpected and surprising characters that we would like to explore next year, that I don't even think people are thinking about."

"Once Upon a Time" airs Sundays at 8:00/7:00c on ABC.