'Once Upon A Time' Two-Hour Season Finale Preview

Colin O'Donoghue and Jennifer Morrison.
Photo Credit: ABC/Katie Yu

Season 3 of ABC drama Once Upon A Time concludes with back-to-back episodes ("Snow Drifts" and"There's No Place Like Home") on Sunday, May 11, starting at 8 p.m. ET/PT.

While Mary Margaret and David celebrate the naming of their son at a coronation in Granny's Diner, Emma and Hook are pulled into Zelena's time portal and find themselves in the Enchanted Forest of the past. But in their quest to discover a way back, they must be careful not to change ANYTHING or risk altering the lives of their friends and family -- as well as their very own existence.

Watch a sneak peek video from the Once Upon A Time season finale below:

'Once Upon A Time' Preview: In the Land of Oz of the Past, A Young Girl From Kansas Threatens to be Zelena's Undoing

Rebecca Mader, Sunny Mabrey and Matreya Scarrwener.
Photo Credit: ABC/Katie Yu

Season 3 of ABC drama series Once Upon A Time continues on Sunday, May 4 at 8 p.m. ET/PT.

In the episode, "Kansas" with Mary Margaret in labor and due to give birth at any moment, the residents of Storybrooke go on high alert in an attempt to ensure that Zelena doesn't try to steal her newborn baby for use in her ultimate game plan to turn back time and change her destiny -- while obliterating Regina's existence.

Meanwhile, in the land of Oz of the past, Glinda tries to convince Zelena to fight her evil tendencies and join her and her sister witches as a protector of Oz. But the appearance of a young girl from Kansas could turn out to be her undoing.

Watch a sneak peek video below:

'Once Upon A Time' Preview: Snow and Charming Go In Search of Good Witch Glinda

Sunny Mabrey as Glinda. Photo Credit: ABC/Jack Rowand

Season 3 of ABC drama series Once Upon A Time continues on Sunday, April 27 at 8 p.m. ET/PT.

In the episode, "A Curious Thing," Zelena threatens to kill Henry if Hook - whose lips have been cursed by the Wicked Witch -- doesn't proceed with kissing Emma, which will drain all of her magical powers away, and things begin to heat up between Regina and Robin Hood. Meanwhile, back in the Fairy Tale Land that was during the past year, Snow and Charming go in search of Glinda, the Good Witch of the South, to see if she can help them defeat Zelena, and the curse that will ultimately send the Fairy Tale characters back to Storybrooke is cast -- but from an unlikely source.

Watch a sneak peek video below:

ONCE UPON A TIME "Witch Hunt" Preview

Ginnifer Goodwin. Photo Credit: ABC/Jack Rowand

Emma discovers that the Storybrooke residents have no memory about how they returned to the town, their past year back in fairy tale land, or who was responsible for the new curse on a new episode of ONCE UPON A TIME, airing Sunday, March 16 at 8 p.m. ET/PT.

Emma arrives in Storybrooke with Henry and reunites with her friends and family, only to discover that no one remembers how they were transported back - or the past year they had spent back in Fairy Tale Land. But Emma is sure that someone in town is responsible for this new curse and teams up with Regina in an attempt to uncover their identity. Meanwhile, in the Fairy Tale Land that was during the past year, Regina, with the aid of Robin Hood, attempts to break into her castle, which has been overtaken by the Wicked Witch.
Watch a sneak peek video below:

ONCE UPON A TIME "New York City Serenade" Preview

Jennifer Morrison and Colin O'Donoghue.
Photo Credit: ABC/Jack Rowand

The third season of ONCE UPON A TIME continues with a new episode ("New York City Serenade") on Sunday, March 9 at 8 p.m. ET/PT on ABC.

After Rumplestiltskin sacrificed his life to stop Pan from enacting another curse, Regina obliterated her original curse, which erased Storybrooke from existence and whisked its residents back to Fairy Tale Land - leaving Emma and Henry back in our world with no memories of Storybrooke. But all is not well back in the Enchanted Forest when Hook comes calling on Emma in New York City in an attempt to jog her memory so that she can once again help her fairy tale family and friends out of a desperate situation.

Watch a sneak peek video below:

ONCE UPON A TIME Winter Finale Sneak Peek

Colin O'Donoghue, Michael Raymond-James, Rose McIver and
Josh Dallas. Photo Credit: ABC/Jack Rowland

The third season of ONCE UPON A TIME continues with a new episode ("Going Home") on Sunday, December 15th at 8 p.m. ET/PT on ABC.

In the Winter Finale, the race is on to stop Pan from enacting another curse on the residents of Storybrooke, which could kill every living soul in town.

Note: ONCE UPON A TIME returns with all new episodes for its Spring Premiere on Sunday, March 9.

Watch a sneak peek of "Going Home" below:

ONCE UPON A TIME "The New Neverland" Sneak Peek

Photo Credit: ABC/Jack Rowland

The third season of ONCE UPON A TIME continues on Sunday, December 8th at 8 p.m. ET/PT on ABC with a new episode, "The New Neverland."

The residents of Storybrooke are overjoyed upon the return of Henry and our heroes from Neverland. But unbeknownst to them, a plan is secretly being put into place by a well-hidden Pan that will shake up the very lives of the townspeople.

ONCE UPON A TIME "Think Lovely Thoughts" Sneak Peek

Photo Credit: ABC/Jack Rowland

The third season of ONCE UPON A TIME continues on Sunday, November 17th at 8 p.m. ET/PT on ABC with a new episode, "Think Lovely Thoughts."

Pan leads Henry to a secret cave, where he has convinced the boy that he alone can save magic and Neverland itself. But a showdown between good and evil is about to go down as Emma, Mary Margaret, David, Regina, Mr. Gold and Hook find themselves directly on a path to Pan in an effort to save Henry.

ONCE UPON A TIME "Dark Hollow" Sneak Peek

Photo Credit: ABC/Jack Rowland

The third season of ONCE UPON A TIME continues on Sunday, November 10 at 8 p.m. ET/PT on ABC with a new episode, "Dark Hollow."

Mr. Gold and Regina send Ariel back to Storybrooke with an item that will allow Belle to locate a hidden artifact that could help take down Pan. But unbeknownst to them, two men have broken into the town with the intent to stop them - at all costs.

Meanwhile, Emma, Neal and Hook attempt to find Dark Hollow, where Peter Pan's shadow dwells, in order to capture it, and Mary Margaret is upset with David for keeping his poisoning a secret from her.

Watch a sneak peek below:

ONCE UPON A TIME "Ariel" Sneak Peek

JoAnna Garcia Swisher as Ariel. Photo Credit: ABC/Jack Rowland

The third season of ONCE UPON A TIME continues on Sunday, November 3 at 8 p.m. ET/PT on ABC with a new episode, "Ariel."

Back in the Fairy Tale Land that was, when Ariel (JoAnna Garcia Swisher) saves Snow White from drowning in the ocean's depths, Snow returns the favor by helping her new friend get acquainted with Prince Eric, with whom she has fallen madly in love.

Sneak Peek: ONCE UPON A TIME ("Good Form")

Jennifer Morrison, Colin O'Donoghue. Photo Credit: ABC/Jack Rowland

The third season of ONCE UPON A TIME continues on Sunday, October 27 at 8 p.m. ET/PT on ABC.

In "Good Form," with the deadly Dreamshade coursing through David’s body and close to death, Hook takes him on one last journey to find a sextant that could help them decipher a map that would lead them off Neverland.

Sneak Peek: ONCE UPON A TIME ("Nasty Habits")

Photo Credit: ABC/Jack Rowand

The third season of ONCE UPON A TIME continues on Sunday, October 20th at 8 p.m. ET/PT on ABC.

In "Nasty Habits," Mr. Gold makes a decision to confront Pan, but will he go there to save Henry or give in to the prophecy that the boy will be his undoing? Neal finds himself back in Neverland and in the custody of one of Pan's most loyal Lost Boys. And David struggles for his life as the poison continues to take its toll on him.

ONCE UPON A TIME "Quite a Common Fairy" Preview

Photo Credit: ABC

The third season of ONCE UPON A TIME continues on Sunday, October 13th at 8 p.m. ET/PT on ABC.

In "Quite a Common Fairy," in their continuing quest to find Peter Pan's hideout and save Henry, Hook suggests tracking down Tinker Bell in the hope that she will lead them straight to his camp.

Pan reveals to Henry why he has brought him to Neverland and in the Enchanted Forest, Neal has a plan that could transport him to Emma, but it would involve using one of Robin Hood's most precious possessions.

ONCE UPON A TIME "Lost Girl" Preview

Photo Credit: ABC

The third season of ONCE UPON A TIME continues on Sunday, October 6th at 8 p.m. ET/PT on ABC.

In "Lost Girl," while Emma, Mary Margaret, David, Regina and Hook continue their search for Henry in Neverland, Peter Pan appears before a startled Emma and offers her a map that will reveal her son’s whereabouts. But the only way to make the map appear is for Emma to stop denying who she really is and come to grips with her true feelings about her identity – and Mr. Gold receives some unexpected advice from a friend that could lead him to understand his life’s journey while in Neverland.