The latest spoilers for "Once Upon a Time" season 5 revealed the addition of two young actresses to the cast to pave the way for flashback scenes involving Zelena and Regina.
Ava Acres and Isabella Blake-Thomas will appear on guest-starring roles as young Regina and young Zelena, respectively for episode 19 called "Sisters."
"Seen at age 10, Regina is described as neglected and lonely, with zero interest in her mother's royal duties" the "Once Upon a Time" season 5 spoilers from TVLine said.
"Twelve-year-old Zelena meanwhile is coming to terms with the magical ability her father despises so much."
The last time fans saw Zelena was when she was banished back to Oz by sister Regina through the help of the Apprentice's wand, and a very powerful cyclone.
Creator Edward Kitsis said that fans haven't seen the last of Zelena after she was sent back to Oz.
"The Zelena story in Oz, with Dorothy, will tie into our Underworld story pretty significantly," he said.
Cartermatt noted that the flashback scene at this point might seem illogical especially with the Underworld story arc.
"What we do know is that despite being relegated off to Oz for the time being, there is still something significant coming for the Zelena character played in the present by Rebecca Mader," the spoilers for "Game of Thrones" season 5 said.
And if Zelena does find herself back in Storybrooke, getting revenge on Dorothy and Regina would be foremost in her mind.
With the Underworld story arc, fans can expect a lot of familiar faces.
"It's a place that, once they get there, they're going to discover that possibly some of these people can be saved and brought out of there, because maybe they're misplaced in this world," Josh Dallas told Entertainment Weekly.
Previous "Once Upon a Time" season 5 spoilers reveal that Josh Dallas' character, David, will meet his twin brother in the Underworld.
"Once Upon a Time" season 5B airs next month on ABC.
