While the buzziest topic out of the Once Upon a Time season 3 finale was the appearance of Frozen's Queen Elsa, there are also a lot of threads left hanging that will be picked up in season 4 this fall.

Queen Elsa Of Frozen To Star In Season 4 After Finale Tease?

Once Upon a Time co-creators Edward Kitsis and Adam Horowitz spoke with TV Guide about the show's various relationships going into season 4 and how they would be explored. For one, fans of Regina (Lana Parrilla) and Robin Hood (Sean Maguire) should be pleased.

When asked if fans would see more Robin Hood struggling between his love of Regina and Maid Marian (Christie Laing), Kitsis said, "Absolutely."

Kristen Bell To Guest As Anna From Frozen?

Horowitz added: "The journey of Robin and Regina is something we really want to explore when the season starts."

Kitsis noted: "It took us this many episodes to get Regina to put her wall down, just as we saw with Emma."

The producers will also be exploring Rumple (Robert Carlyle) and his various conflicts and developments, which include marrying Belle (Emilie de Ravin) and losing his son Neal (Michael Raymond-James).

"We didn't really get to explore what is going on in his head because he was held a prisoner by the Wicked Witch, so we really want to focus on Season 4 and get in depth into what he's thinking," Kitsis said. "What is it like to lose your son? To die and come back to life? What is it like to marry the person? What is it like when you get what is supposed to be your happy ending?"

The producers also confirmed that they would like to see more characters from Frozen appear in the new season.

Once Upon a Time season 4 will premiere in fall 2014 on ABC in the same 8 p.m. timeslot.