“Once Upon a Time” will return for another magical installment with the Season 5 premiere of the fantasy drama in September. However, this season will be far from a fairy tale for the mystical characters of “OUAT,” according to a promotional video for the hit ABC series.

In the 30-second trailer, viewers watch as our favorite Storybrooke residents encounter new obstacles and deadly foes in the drama-ridden promo. “The clash of good versus evil has never been this intense,” the video warns as the trailer cuts to a scene of Zelena (Rebecca Mader) attacking Hook (Colin O’Donoghue).

But the wicked witch won’t be the Storybrooke residents’ only concern. The synopsis of the new installment, set to premiere Sunday, Sept. 17, reveals that Emma (Jennifer Morrison) will spend this episode of “OUAT” fighting her transformation into the Dark One.

“Episode 1, Season 5, she is not the Dark One,” Robert Carlyle, who plays the role of Rumple, the previous Dark One, told Entertainment Weekly in July. “Maybe she becomes that, but at this point, she’s trying to get rid of it. She’s trying to get rid of the dark magic at the moment.”

According to the Season 5 summary, Emma won’t be acting alone as she attempts to save herself from becoming evil. Snow White (Ginnifer Goodwin), Prince Charming (Josh Dallas), Regina (Lana Parrilla) and Hook will rally together to prevent their friend from meeting her grim fate, which means they’ll be taking a trip to Camelot to track down the all-powerful wizard Merlin (Elliot Knight), a sorcerer who allegedly can help save Emma.

But on their journey, the friends will encounter more than they expected when they get introduced to King Arthur of Camelot (Liam Garrigan).

“You were expecting us?” Snow White asks the regal newcomer in the promo video after he admits he’s “come to find” them.

Garrigan’s character will make his “OUAT” debut in the Season 5 premiere. The king is described as “good and just,” according to TV Guide, but underneath his charming exterior lays a “master manipulator.” Good thing the Scottish Princess Merida (Amy Mason), the main character in the Pixar film “Brave,” is lurking in the woods with her bow and arrows. Looks like Snow White and the gang could use some help!

“Once Upon a Time” Season 5 will premiere on ABC Sunday, Sept. 27.