As the end of "Once Upon A Time" season 4 closes in, the executive producers warn that fans "should always worry about Emma." Previous episodes of the fairytale drama series led up to the savior growing uncontrollably darker and the season will end with "a very big sacrifice" she will make. 

In an interview with Entertainment Weekly, showrunners Adam Horowitz and Edward Kitsis dished out where in the world Emma is headed and if she has gone so far out into becoming evil. 

"In the final episode, she is dealing with the journey of being a hero, trying to get other people to believe, and then she's going to be faced with making a very big sacrifice," Kitsis told EW when asked about her decision to bring Lily to Storybrooke (which the publication thinks is not a bad thing).

Emma decided to spare Lily's life but this was apparently not enough for Maleficent's daughter to spare that of Emma's parents. After all, Kitsis told TV Line that "anger doesn't go away with one night," adding that "just because she and Emma had a nice scene on the highway doesn't mean that it's over." 

Meanwhile, Snow and Charming cannot blame Lily's thirst to kill them as they themselves haven't forgotten the horrors they have done to her, let alone stomach the aftermath that Emma's childhood friend had to endure. 

"Snow and Charming look at Lily, and they want her to reunite with her mother because they thought they had killed her, so they feel a lot of guilt. But in this weekend's episode, there's an entire story devoted to Lily and Maleficent's reunion and what they're going to do with the future," Kitsis dished. 

Ultimately, season 4 lays out Emma's destination up to the finale.

Kitsis told TV Line, "Emma is definitely tested on this road of darkness, and where she ends up is going to be up in the air for the next three episodes. But she has a strong heart, so it's going to take more than just a woman holding a gun to her kid's head to turn her."

The season 4 finale of "Once Upon A Time" will air on May 10.