'Once Upon a Time' season 6 spoilers: more details about the alternate universe revealed

It will take a while before ABC airs the second half of "Once Upon a Time" season 6, but executive producers Adam Horowitz and Edward Kitsis gamely answered some of the questions regarding the plot of the second half of the season through a question-and-answer (Q&A) session conducted by Entertainment Weekly via Twitter.

When asked if Captain Hook (Colin O'Donoghue) will be present in the alternate reality of Storybrooke, Horowitz confirmed that Emma Swan's (Jennifer Morrison) boyfriends will follow her in the other universe.

The executive producers also clarified that even if Hook could reach Emma in the alternate universe, a true love's kiss will not bring her and Regina (Lana Parilla) back in the real world since the two were not stuck there due to a curse.

"I don't think there is one," Kitsis stated. "That's the whole point. It's the world where there is no curse." Horowitz, on the other hand, described the alternative reality as the wish realm which happens to be a real place.

The executive producers also explained the reason why Regina's heart remains black even if she managed to successfully separate herself from her evil alter ego, the Evil Queen. According to Horowitz, the state of Regina's heart will be an important story in the series.

On the other hand, Kitsis claimed that they will discuss the real reason about Regina's heart in the upcoming episodes of "Once Upon a Time" season 6. "Yeah, we're actually going to fully get into what we've posed, which is can you separate the good from the bad, the dark from the light, or is it something that's inside us that we have to live with and deal with?" the executive producer stated.

Horowitz and Kitsis also confirmed that Belle (Emilie De Ravin) will finally learn who sped up her pregnancy when "Once Upon a Time" season 6 returns for the second half of the season sometime in March.