The second half of the second season of ABC's hit fantasy series "Once Upon a Time" rings in the new year this Sunday by amping up the storytelling as evil Cora (Barbara Hershey) and diabolical Captain Hook (Colin O'Donoghue) arrive in Storybrooke with big plans to shake up our favorite residents of Storybrooke.

Our Jim Halterman was on the set of the series in Vancouver recently to talk to the cast and Executive Producer Steve Pearlman about what fans can expect to see as these new episodes unfold.

In talking about this half of the season, Pearlman explained that everything essentially comes down to relationships, both good and bad. "It's really about what happens when Cora meets up with Gold (Robert Carlyle) and what happens when Cora meets up with Regina (Lana Parrilla) and what happens when Hook meets up with Regina." While those interactions don't happen in this week's new episode, the seeds of these altercations are definitely planted.

At the start of Sunday's episode, "The Cricket Game," begins, Cora and Hook arrive by ship in Storybrooke but decide to keep a low profile as they get more familiar with the residents of this strange new land. "They've heard of Storybrooke," Pearlman said, "[but] they have never experienced it before."

He did say that there won't be a lot of time spent on the characters coming face to face with modern technology - like cell phones and computers - since they have already had moments, for example, where new resident Belle (Emilie de Ravin) has her first hamburger. "I don't think we want to keep playing those kind of 'Oh a cell phone? What is this thing?' but the fun of seeing these two characters in Storybrooke is it is kind of like them against the world in a way and they're different by virtue of their clothing and they're different by virtue of experience and this is so completely foreign to them."

However, the series actors discussed, once Cora reveals her presence, the one thing everyone will be sharing is fear. "Cora is a frightening presence," said Josh Dallas, who plays Prince Charming. "Lemme tell ya, she is gonna cause some trouble for sure." Dallas' co-star - and on-screen daughter - Jennifer Morrison agreed. "I think Cora is terrifying. I mean, to me, she is the most terrifying villain we've had, only because she's so sweet and so charming and she's easy to believe and then is just completely coldblooded and without any sort of remorse for her actions."

And while Cora and Hook don't make their presence known right away, don't expect things in the town to remain calm. "Well, there's immediately new problems" Morrison shared. "It's not like Emma gets a break." One thing that is a welcome addition for her, though, is her now-full awareness that her parents are Charming and Snow and that she also has the chance to finally be a mother to her son, Henry (Jared S. Gilmore). The actress previewed, "I think what you see more is that Emma has always been closed off and has always been so guarded because her emotions are so close under the surface that she's had to hold very tightly to that armor and so now that that has really been infiltrated, her armor has really been infiltrated, she swings between that really tough, hard side and really vulnerable, very quickly now."

And since Emma has been off in Fairytale Land for the first half of the season, Charming has stepped into her role as Sherriff of Storybrooke. What happens once she's back? They work together, of course. Dallas said that Charming (a.k.a. David) "is there as support, as back up, so they have slightly different ideas of how to bring certain people to justice." Their different styles end up being a benefit, he thought. "I think they can both learn from each other and I think that's another great thing when I go back to finding out more about [Emma] as a woman and about their friendship I think that's more important for him to develop more than anything else so I think that they're going to team up a little bit for sure." Dallas also teased that we haven't seen the last of Charming's evil father, King George and, if Dallas personally had his way, Charming's twin brother, James.

Another story thread coming up is the fact that our characters are no longer magically stuck in Storybrooke. In fact, Dallas teased, some of the characters may actually want to return to their home in Fairytale Land with Charming leading the pack. "He wants to go back and this place, Storybrooke," he laughed. "Even though it's been his home for 28 years, he was asleep for most of it! He was asleep for 28 years and he went through a whole year of not really knowing who he really was so I think he definitely wants to go back." And while his beloved Snow White knows that their home has changed very much since they were last there, this bit of news only incites Charming's desire more, Dallas revealed. "This is all the more reason why he wants to go back and to fix it because we fought for this kingdom and we fought for it so let's go home."

In the midst of a lot of this action is Regina, who has been trying hard to stay away from magic for the sake of Henry. "The Cricket Game," however, focuses on whether or not she can truly change. "I really think she is trying," Parrilla said. "I think it's genuine. I don't think it's manipulated or false on any level because there are moments where I want to play it where I want to confuse the audience to think, 'Oh, any moment she's going to pull out the fireball and throw it at someone.'" However, watch for Regina to find it harder to stay away from magic, especially once she and Cora are reunited.

And while Hook and Emma don't cross paths in the return episode, there is the matter of an already-teased attraction between the two that could become more prominent later in the season. In fact, Morrison has her own theory as to why Emma might be drawn to such a known scoundrel. "They're definitely kindred spirits," she said. "They're both thieves and they've come from troubled pasts and they've both lost a true love, so I think that there's a lot that they recognize in each other. So there's that camaraderie and also the combativeness of that."

Of course, there's also romance brewing with the conniving Gold and Belle and Carlyle explained their upcoming journey. While Gold will be back on the trail of his missing son, there will also be challenges for his budding relationship with Belle since the writers, the actor said, have structured things so "you don't always get what you want in the story." Carlyle doesn't see this as a bad thing at all for the romance. "I think when you look at it in the cold light of day, it's probably exactly what would be happening. It's not really sweetened up and it would be wrong if you sweeten up this relationship. This relationship has to be like any other relationship. It's got to go up and down and peaks and troughs."

Getting back to the impending threat of Cora, Carlyle simply said, "I think she's just bad news. She's bad news to have around. She's nasty." And while Gold (a.k.a. Rumplestiltskin) has done his share of bad things, he sees the two characters as different. "I think that Rumple is about himself but I don't think he's necessarily world-domination nasty and I think that Cora probably is."

One thing's for sure - there's much excitement and drama to come as the second half of the season unspools beginning this Sunday.

"Once Upon a Time" airs Sundays at 8:00/7:00c on ABC.