"Once Upon a Time" season 6 has just returned from its midseason break and there's a lot to look forward to. Show creators Adam Horowitz and Edward Kitsis dish on what's going to happen in the second half of season 6, especially the war that's about to take place in Storybrooke.

Earlier this season, Emma (Jennifer Morison) saw a vision of her own demise. Gold (Robert Carlyle) and Belle's (Emilie de Ravin) son, Gideon (Giles Matthey), is her supposed killer, but the reason behind this is still unknown. While show creators Horowitz and Kitsis won't reveal it just yet, viewers will surely get to know more about Gideon's character and his motives this season.

There's a war coming to Storybrooke soon as well. Horowitz and Kitsis recently spoke with E! News and gave a bit of information about what it is going to be like. "I think there's an intensity that's about to overcome everything and it's going to be not just be about the external conflicts of what's going on with Gideon or whoever else they may be facing, but also internally as all the characters have to look inward and deal with their own issues in the face of great adversity," said Horowitz.

A musical episode is also underway, but people can't help but wonder how this will fit into the intense storyline. "We wanted it to be an organic part of the season's storytelling. And we found a way to do that which we're really excited about. So all this intensity and stuff that going on in town, I think you'll see, once we get to the musical, that it is nicely balanced by what's happening in the musical," Horowitz clarified in the same interview with E! News. "The storytelling in the musical is the key to all the different storylines going on," he added.

Most of the cast members have musical backgrounds, especially Jennifer Morison, Josh Dallas, and Ginnifer Goodwin.

Meanwhile, season 6 episode 12 is coming this Sunday. In the latest promotional video for the episode, Prince Charming/David (Josh Dallas) is seen trying to bring back his wife, Snow (Ginnifer Goodwin). And it looks like he's going to do whatever it takes to get her back.

It also shows the pairing up of an unlikely duo, Hook (Colin O'Donoghue) and Charming. Before taking the next step with Emma, Hook will try to convince Charming, his future father-in-law, that he is more than just a pirate. Hook does this by agreeing to Charming's request of helping him uncover the truth behind his father's death. But will the truth be liberating for the prince or will it create more conflict?

There are speculations that Hook was the one who killed Charming's father. According to Horowitz in an interview with TV Line, viewers will know more about the issue by Easter.

"Once Upon a Time" airs Sundays at 8 p.m. EST on ABC.