ABC's fairytale drama series "Once Upon A Time" has wrapped up its fourth season in May. The fifth season is coming on September 27, 2015.

These hints from the executive producers reveal what can be expected in the upcoming season:

1. The world turns upside down.

In the finale of the last season, Emma was left with no choice but to sacrifice herself into the darkness just to save Regina's life.

Entertainment Weekly has released exclusive photos revealing Emma's dark transformation.

'Every part of her is fighting her dark urges," executive producer Edward Kitsis tells Entertainment Weekly. "What happens when [darkness] mixes with the lightest magic of all, and will Emma have the strength to fight it?"

Meanwhile, executive producer Adam Horowitz says becoming a Dark One is different to each person. "Emma will have her own unique spin on what it means to be a Dark One."

2. Fans may get to see a new hero.

According to Bustle, some rumors are surfacing that Regina, who is not really known for being the kindest person around, is going to be the real hero of this season. Indeed, the world has turned upside down.

"The quest for Merlin is the quest to free Emma," Kitsis also tells Entertainment Weekly. However, that would mean that Merlin needs a new hero.

3. King Arthur is coming.

Liam Garrigan of "24: Live Another Day" and "Strike Back" is reported to have been cast as King Arthur.

King Arthur has not been mentioned in the series. However, the story of another character, Lancelot, reveals that there may be an untold story in the kingdom's Round Table.

"As we do on Once Upon a Time, we're doing our own twist on Camelot, on Arthur's background and on his relationships with Merlin, Guinevere and Lancelot," the executive producers said.

4. Lancelot may be returning.

Lancelot, a former knight of the Round Table, has been disgraced because of a woman. It could be that King Arthur has been involved.

In the last season, Cora claimed that Lancelot is dead. However, his corpse was never revealed. Speaking of twists, according to another report from Entertainment Weekly, Lancelot coming back alive is a possibility.

5. Only one thing may save Emma from the darkness.
 
"We are going to be exploring love and what happens when you use it as a weapon and what are the things that it makes you do," executive producer Edward added during the talk with Entertainment Weekly.

Once upon a time, Emma has been the one saving people. Now, Emma is the one that needs saving. Maybe what she needs is a magic more powerful than the light and dark combined.

"In the past, we've said love is the most powerful magic of all. It makes you do many things you normally wouldn't think you would."