Season 4 is the fourth season of ABC's "Once Upon a Time". The season premiered on 28 September 2014. It was announced after the end of the third season, that like the previous season, this season would also be split into two parts, with the first half consisting of 12 episodes and the second half consisting of 11 episodes.
The first half of the season told the story of the Frozen characters; with addition of a new main antagonist to the storyline, The Snow Queen. The first half of the season cocnluded on 14 December 2014.
The second half of the season deals with the Queens Of Darkness: Ursula, Cruella and Maleficent, who begin working with Rumplestiltskin to find villains a happy ending. It began airing on March 1st, 2015 and concluded May 10th, 2015.
- Chapter III: The Queens of Darkness Chapter: (Ep. 411 - 418) This chapter deals with the arrival of the Queens of Darkness, a team of three evil witches led by Rumplestiltskin, and their plan to find the Author and bring forth a happy ending for villains.
- Chapter IV: The Heroes and Villains Chapter: (Ep. 419 - 422) This chapter deals with Rumple's new alliances with Zelena and Isaac, after his former alliance with Queens of Darkness is broken. It also deals with Isaac's rewriting of the storybook.
- The main antagonists of this season are Ingrid, Rumplestiltskin and Queens of Darkness.
- Ginnifer Goodwin as Snow White
- Jennifer Morrison as Emma Swan
- Lana Parrilla as Regina Mills
- Josh Dallas as Prince Charming
- Emilie de Ravin as Belle
- Colin O'Donoghue as Captain Hook
- Jared S. Gilmore as Henry Mills
- Michael Socha as Will Scarlet
- Robert Carlyle as Rumplestiltskin
- Sean Maguire as Robin Hood
- Georgina Haig as Elsa
- Kristin Bauer van Straten as Maleficent
- Elizabeth Lail as Anna
- Elizabeth Mitchell as Ingrid the Snow Queen
- Scott Michael Foster as Kristoff
- Lee Arenberg as Grumpy/Leroy
- Beverley Elliott as Granny Lucas
- Patrick Fischler as Isaac Heller
- Timothy Webber as the The Sorcerer's Apprentice
- Victoria Smurfit as Cruella De Vil
- Merrin Dungey as Ursula
- Christie Laing as Zelena/Marian
- Rebecca Mader as Zelena
- Main Antagonist: Ingrid
- Main Protagonist: Elsa, Emma Swan, Anna and Regina Mills
- This season is an adaption of Disney's "Frozen" and the novel "The Snow Queen" by Hans Christian Andersen.
- Main Antagonist: Rumplestiltskin and the Queens of Darkness
- 4b has the most main antagonists than any other season. While most season arcs have only one, occasionally two, this season has multiple, including: Rumplestiltskin, The Queens of Darkness (Maleficent, Cruella, Ursula), Isaac Heller, and Zelena. Rumple clearly stands at the top of the hierarchy.