"Once Upon A Time" Season 6, Episode 19 is named "The Black Fairy" and there is no doubt it centers on the evil Black Fairy, also known as Dark Fairy. In the meantime, the show is expected to reveal the aftermath of Zelena's fight with the big bad.

The synopsis published by Cartermatt states: “In flashback, after Rumple’s mother, Fiona, gets from his fairy godmother that his future is prophesized, she does everything in her power to keep it from happening and ultimately, Fiona will have to make a choice that will change the direction of both their lives forever.

Meanwhile, in Storybrooke, Rumple confronts a similar difficulty."

Plot and highlights episode 18

At the end of last week’s chapter, the Black Fairy hinted that there is a reason she left Rumple when he was a child, a mystery that looks to finally be explained via flashbacks. “No curse is ever going to be as terrifying as finding out why you were rejected." In the next episode, the trailer shows the Savior attempting to convince Rumple to help her take the opponent down.

Now that they remember what must be made to win the Black Fairy, Emma is preparing up for the final battle because she knows the antagonist is very compelling and that she requires all the cooperation she can get. Having Rumple on her team will provide her some living space and she is prepared to form an agreement with him.

Rumple looks good with her project, as he also needs to end the Black Fairy's command.

Spoilers and trailer episode 19

On episode 19 of "Once Upon a Time", Fiona's past will be told, exposing the true reason why she decided to abandon his son. Based on the teaser, it appears that her goal for leaving him is tied to his destiny.

The official promo also shows the Black Fairy coming to Storybrooke in a last-ditch effort to keep the truth about her and Rumple's lives a mystery.

Will she be piecing for the Blue Fairy (K. C.Tracy), the only one other than herself who knows the veracity? Or will the next chapter be ushering in the last battle between Emma and the Black Fairy?

In a discussion with EW, Rebecca Mader, who plays the character of Zelena, talked about how it influences her. "It's great to see growth in someone that is so hurt, because fixing other people first isn't something that she is accustomed to, and I presume to become a mother has really prepared her a lot about love, and not having to do all alone, and being part of something bigger than herself with these other people," Mader told.

Episode 19 of "Once Upon a Time" season 6 will air on ABC on Sunday, April 30 at 8.00 p.m. EST.