While the fairy tale television drama series on ABC, 'Once Upon A Time' Season 4 comes to a close, fans will be seeing Emma (Jennifer Morrison) stepping into the dark side. The savior of Storybrooke will be striking Snow White (Ginnifer Goodwin) and Prince Charming (Josh Dallas) with horror after pushing Cruella de Vil from a cliff to save Henry.

According to Christian Today, 'Once Upon A Time' executive producer Adam Horowitz recently confessed to TV Line that "Emma has crossed a line," and called her an "ever-unseemly Savior" for killing Cruella in cold blood, besides her "riff with the 'rents."

In 'Once Upon A Time' Season 4 Episode 20 titled 'Lily,' the show will focus on Emma's reunion with her old friend. However, it is unfortunate as it will not be the sort of reunion that involves hugs and kisses. Instead, this is one reunion that may result in one of them being dead. Nevertheless, Horowitz revealed that it "is not all deathly conflict."

Meanwhile, in an interview with TV Line, another executive producer of the series Eddy Kitsis revealed, "There are moments of warmth and there are moments of bonding. And there's a lot of emotion. It's a real story of friendship." Kitsis was referring to how things will pitch between Lily and Emma in the upcoming episode.

The promo for 'Once Upon A Time' Season 4 Episode 20 shows flashbacks of Lily and Emma in foster care. Fans can hear a voice narrating that the after this the good friends will meet as mortal enemies. He teases that the girls' fate are "intertwined."

While Lily is firm on "punishing" Emma's parents, the savior will try to lend her a hand. The synopsis for 'Once Upcon A Time' Season 4 episode 20 further reveals that eventually Emma will be helping Lily to reunite with her mother Maleficent. Nevertheless, there will be plenty fighting before that happens.

'Once Upon A Time' Season 4 Episode 20 'Lily' will air on Monday, April 26, on ABC.