Once Upon a Time (season 6)

Premise

Just when it looks like Storybrooke can enjoy some peace, once more it is threatened by dark forces. The malevolent Mr. Hyde, now separated from Dr. Jekyll, has arrived and brought his fellow inhabitants from the Land of Untold Stories. To make matters worse, Regina's dark half - the Evil Queen - continues to exist despite her heart being crushed; unburdened by a conscience, the Evil Queen has declared war on the heroes. Meanwhile, Aladdin's past as the previous Savior becomes a new factor in Emma's role as the current Savior, and is about to be pushed to the limits, which could lead her to a future that has no happy ending for her, while Gold must deal with trying to win Belle's heart again so they can be a family for their future child. Later on, the Black Fairy abducts Gideon, the son of Gold and Belle, which further complicates things for Storybrooke's residents. As Emma, Regina and an alternate universe version of Robin Hood return to Storybrooke, Gideon arrives as a grown man, and is revealed to be the one fated to kill Emma.

Regular

Development

Executive producers Adam Horowitz and Edward Kitsis announced that they were ending the half-season arc structure that was seen in seasons three through five, with Horowitz saying, "We’re also planning a 22-episode story as opposed to breaking it up into two halves this year. It has been really exciting and fun." Kitsis added: "We are changing around what we’re doing this year and going back to that season 1 mentality of small town stories and smaller arcs." This season will focus on Storybrooke as the main setting, but will also show new realms and there will be the exploration of the Savior's mythology. Kitsis and Horowitz hired two directors from their Freeform series Dead of Summer, Norman Buckley and Mairzee Almas, helm episodes of the season. Jennifer Lynch directed the eighth episode of the season, "I'll Be Your Mirror".

Musical episode

In January 2017, TV Line reported that the series would feature a musical episode later in the season. Creators Kitsis and Horowitz had spoken about the desire to do a musical installment previously, but didn't "even know where to begin." Kitsis and Horowitz confirmed the report in February. They have also since confirmed that the episode will feature 7 original songs, including solos by Jennifer Morrison and Rebecca Mader, as well as a "sing-off" musical number featuring the Evil Queen and the Charmings. Composers Alan Zachary and Michael Weiner will be writing the original numbers featured, with arrangements provided by the show's long-time composer Mark Isham. Kitsis and Hororwitz spoke about the nature of the episode saying, "It actually is a huge part of the mythology of the show and there are some big things that happen in the episode, frankly, it's been one of the challenges of doing the musical because we never wanted to do something where it was just like a to-the-side, one-off thing, and then get back to the main story. We want to see it part of the main story, which meant we had to really plan out this season with some great detail.

Casting

Emilie de Ravin told fans that she will be returning for the sixth season. It was also announced later that Sam Witwer and Hank Harris have signed a contract to play two new recurring characters on the sixth season of the show. On March 29, 2016, Lana Parrilla confirmed she would be returning for the sixth season. Robert Carlyle was confirmed to be returning for the sixth season as Rumplestiltskin along with Rebecca Mader as Zelena and Jared Gilmore as Henry Mills.

It was announced that Giles Matthey was cast as Morpheus, who is slated to appear in the first episode of the season. On July 20, it was announced that Craig Horner would be portraying the Count of Monte Cristo, who will be introduced in the second episode of the season. At the 2016 San Diego Comic Con International it was revealed that the season would see the introduction of Aladdin (Deniz Akdeniz), and his story featuring the return of Jafar, now portrayed by Oded Fehr (the role had been previously played by Naveen Andrews on Once Upon a Time in Wonderland). Andrews was unavailable due to his previous commitment to Netflix's Sense8. It was also announced that Galavant's Karen David was cast as Princess Jasmine. She will make her debut in the fourth episode of the season.

In early July, it was announced that Raphael Sbarge will be reprising his role as Jiminy Cricket / Dr. Archie Hopper in the season premiere. The character's last appearance was in the season 4 episode "Rocky Road." On July 20, it was announced that Jessy Schram would be reprising her role as Cinderella in the third episode of the season. The episode will explore a connection that her character has to someone from the Land of Untold Stories, as well as the start of her friendship with Snow White. That same episode will also introduce Cinderella's stepmother and stepsisters. David Anders will return this season as Victor Frankenstein. The character will have a connection with Jekyll and Hyde. On August 15, it was announced that Jonny Coyne would be reprising his role as Dr. Lydgate from Once Upon a Time in Wonderland, in the fourth episode of the season. On August 26, it was announced that Faran Tahir was cast as Captain Nemo, and would have ties to Captain Hook. On September 22, it was announced that Tzi Ma will be reprising his role as the Dragon sometime in the season. Gabrielle Rose will also be returning as David's mother, Ruth, who will appear via flashback in episode 7. On September 27, it was announced that Sean Maguire will be returning as Robin Hood. The former main character, who died on-screen near the end of season 5, will not be brought back from the dead but will appear in a multi-episode arc in a different capacity.

For the second half of the season, Wil Traval will be returning for multiple episodes, starting in episode 11, as the Sheriff of Nottingham. On October 31, it was announced that Mckenna Grace would be returning as a younger version of Emma. On December 11, Robert Carlyle revealed that Brandon Spink would be portraying a young Baelfire in episode 13. On January 6, 2017, it was announced that JoAnna Garcia would be returning as Ariel. The story line will involve a team-up between Ariel, Jasmine, and Hook. On January 7, Horowitz confirmed that Gil McKinney would also be returning as Prince Eric. Two days later, it was announced that Rose McIver would also be coming back as Tinker Bell. On January 20, it was revealed that Sara Tomko was cast as Tiger Lily. The recurring character will appear in at least two episodes starting in episode 17. On January 23, Horowitz announced that Patrick Fischler will return as former author Isaac Heller at some point in the second half of the season. On March 14, it was announced that episode 18 will introduce the Tin Man, played by Alex Désert, and the Cowardly Lion from the Wizard of Oz tale.

On February 16, TVLine released casting call descriptions for two characters who will appear in the season 6 finale, with potential to continue into season 7 if the show is to be renewed. One is a man in his late 20s-early 30s who "was once optimistic and hopeful but now is a friendless, cynical recluse" but "still possesses a dormant, deep-seated spark of hope that waits for the right person to reignite it." The other is a 10-year-old girl who "comes from a broken home" but "those struggles have only made her stronger — something which will come in handy when darkness threatens everything she holds dear." On March 8, it was announced that Andrew J. West had been cast in the unidentified male role. On March 9, it was announced that Alison Fernandez had been cast in the unidentified female role.