The show runners of ABC's Once Upon a Time are "making good" on their promise about Regina (Lana Parrilla) for the end of season 4.

Snow Severely Injured In Promo For Next Episode of 'Once Upon a Time'

Once Upon a Time co-creators Edward Kitsis and Adam Horowitz recently spoke with TV Guide (as scanned from SpoilerTV) about the final episodes of season 4 and the relationship between Regina and the Author (Patrick Fischler).

"Once Upon a Time made a promise to its fans at the start of this season when Regina said she was going to force the Author to write her a happy ending." Kitsis says. "We will make good on the happy ending -- but what exactly is the Author writing and who is he writing it for?"

Regina Doesn't Trust Mother's Intentions In New 'Once Upon a Time'

Kitsis further reiterated the theme of this season regarding heroes and villains and explained how Henry (Jared Gilmore) will become important to the story.

"This is all about the heroes and the villains and which side wins," Kitsis adds. "Young Henry is front and center in this, flexing his adventure muscles when he is called upon to be a hero."

With the promos hyping up the two-hour season finale as a game-changer, Horowitz says that it really will have a big impact on the series.

"We are flipping everything," Horowitz says. "It's a change so big it will ripple through every character."

Fans saw in the promo for next week's episode (the third to last of the season) that Snow (Ginnifer Goodwin) hit her head on a rock, so hopefully this big change won't have anything to do with Snow possibly dying.

Once Upon a Time airs Sundays at 8 p.m. ET/PT on ABC.

Watch the promo for the next episode of Once Upon a Time here:

Tags: Once Upon A Time television ABC