Jennifer Morrison stars in "Once Upon a Time"

The finale is here, and the season's biggest battle comes to a head in the two-part season 6 finale of "Once Upon a Time," airing Sunday, May 14, on ABC. The show that brings beloved fairy-tale characters to life is set to wrap up the season in a big way. 

"O.U.A.T." has shown us the lives of some of our favorite fairy-tale characters, including Ariel, Mulan and Jasmine, in stories that differ greatly from the versions we know and love. This season has been a roller-coaster ride for the citizens of Storybrooke. From love to loss, happiness to sadness, everyone is dealing with something, but nothing can prepare them for what's coming. 

At the start of the current season, Emma (Jennifer Morrison, "House") began having visions and tremors -- premonitions of her impending death. In a recurring vision, she fights with a cloaked figure who steals her sword and murders her. Central to the majority of the season is Emma's fear of her fate and, along with her friends and family, she tries to figure out who this mysterious hooded person is, and why he or she wants to kill her. 

Emma didn't have to look far, as Rumplestiltskin (Robert Carlyle, "Trainspotting," 1996) and Belle's (Emilie de Ravin, "Lost") son Gideon (Giles Matthey, "The Duel," 2016), has now been revealed as the one who wants to kill her. A complex storyline sees the baby aducted by the nefarious Black Fairy (Jaime Murray, "Defiance"), who also happens to be Rumple's mother. When Gideon returns full-grown, thanks to some tricks of time, it's discovered that Emma factors into his plan to kill his abductor, the Black Fairy. 

While Emma's battle with Gideon takes some unexpected twists and turns, the sudden arrival of the Black Fairy signals the beginning of the real, climactic final battle. And that's where we find ourselves as the much-anticipated two-part finale premieres.

Season 6 is an end in more ways than one, as show creators Edward Kitsis and Adam Horowitz -- who have both also written episodes of "Lost," among other successful series -- said the season marks the end of the main storyline that has been the central focus of the entire series, regardless of whether the show is renewed for a seventh season. As Henry (Jared S. Gilmore, "Mad Men") finishes the last chapter of the book, some of the show's major storylines wrap up, and some characters prepare to depart the series.

Josh Dallas ("Thor," 2011), who plays Prince Charming and Emma's father, told Entertainment Weekly that the finale is "all about the final battle, the final battle that Emma is clearly involved with, and it's life or death."

Morrison expressed the same sentiments, saying: "They're realizing that they're at the end of the book. They're like, 'What does that mean, the end of the book? Does the end of the book mean a happy ending? Does the end of the book mean she dies?'"

Jaime Murray as seen in "Once Upon a Time"

Whatever happens, Emma has her loved ones by her side, including Snow White (Ginnifer Goodwin, "He's Just Not That Into You," 2009), her mother; Regina (Lana Parrilla, "Miami Medical"), her one-time enemy turned friend; Henry, her son; and Captain Hook (Colin O'Donoghue, "The Rite," 2011), her fiancé. 

Whether the show follows a typical fairy-tale ending or not, a seventh season should point the series in a new direction. ABC entertainment president Channing Dungey told EW that season 7 could offer "a springboard to a new narrative standpoint. ... [That] doesn't necessarily mean that we're not bringing the cast back, it's just: How do you kind of hit the reset button?"   

Morrison, Parrilla, O'Donoghue and Carlyle are currently in negotiations for a new season, but nothing is confirmed. While on "The Drop-In With Will Malnati," Morrison said: "We're just kind of waiting now to see if the network decides to continue with the show -- and if they do continue with the show, if they are going to rework it to be something else, or if they're going to invite people to stay. It's really complicated." 

Though the finale is so close, there are still multiple questions that need to be answered, and stories that must be wrapped up -- it could be tough to tie everything up if this does happen to be the final season. Rest assured though, Dungey says: "If and when we decide to end it, we want to do it the right way, and really give the fans the ending they deserve."

"O.U.A.T" was a hit when it first aired in 2011, earning the best ratings out of any new show that premiered that season. Ratings for the show have been on a bit of a decline, however, with comments from fans and critics alike insisting the show should end due to repetitive storylines and character plots that already seem to be finished. Despite this, the show still maintains a steady viewership.

Don't miss the big, two-part season finale of "Once Upon a Time" when it airs Sunday, May 14, on ABC.