As "Once Upon a Time" season 4 continues to air on television, spoilers regarding the return of some classic fairytale characters have surfaced.

According to spoilers by TVLine, co-creator Eddy Kitsis revealed at the New York Comic-Con that the mystery behind who wrote the storybook will span beyond the first half of the season.

“Operation Mongoose is going to be a rather big story for the year. Whereas we are splitting seasons in half, this is a story that will transcend both halves," said Kitsis.

In addition, spoilers confirm that both Maleficent and Aurora return to "Once Upon a Time" season 4.

Reportedly, Aurora will make a return to "Once Upon a Time" in episode 7 of season 4 "out of her princess gear" in Storybrooke.

"It'll be nice to see Aurora again but unless they do a bit of a time jump, it doesn't seem to add up that she would have the kid already," commented Jennifer on TVLine.

Meanwhile, Kristen Bauer's return as Maleficent might foreshadow the storyline of the second half of "Once Upon a Time" season 4.

"Well, you know, it might, or you can look at it as just a tease for the second half of the season," added Kitsis.

"Kristen Bauer is someone we loved since we used her in the first season," said co-creator Adam Horowitz. "We had an idea [for her return] and if you hang around and watch you’ll see what it is. But yeah, she’s a fun character to play with."