Episodes of the series typically feature a primary storyline in Storybrooke as well as a secondary storyline from another point in a character’s life before the curse was enacted.
During the fourth season of “Once Upon a Time,” a new storyline incorporating the elements of “Frozen” was revealed when the time travel events of Season 3 lead to the accidental arrival of Elsa, played by Georgina Haig, from the Enchanted Forest of the past to present day Storybrooke.
As she searches for her sister Anna, played by Elizabeth Lail, with the aid of the show’s other main characters, they encounter the Snow Queen, played by Elizabeth Mitchell in Storybrooke.
The central focus of the past season, however, was on Regina as she seeks the author of Henry’s “Once Upon a Time” book so that she can finally have her happy ending. However, Mr. Gold, with the help of Cruella De Vil, played by Victoria Smurfit, Maleficent, played by Kristin Bauer van Straten, and Ursula, played by Merrin Dungery, had his own plan to rewrite the rules governing the destinies of all heroes and villains.
Henry and Emma race to restore reality and the truth before the twisted inversion becomes permanent and as every fan of the series knows by now, it came with the ultimate sacrifice of Emma going into the darkness.