Fans of Emma (Jennifer Morrison) and Hook's (Colin O'Donoghue) relationship on ABC's Once Upon a Time may want them to get together and stay together, but it might be easier said than done.

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Morrison, O'Donoghue and other cast members spoke with The Hollywood Reporter recently to tease some of the story lines coming in Season 4 of the series. While Emma and Hook were last seen enjoying each other's company in the Season 3 finale, their happiness may not last.

"They've really invested in maybe wanting to be together," O'Donoghue explained. "Emma is The Savior and Hook is a 200-year-old pirate - it's never going to be plain sailing or easy going. But they're going to try their best to make their relationship work."

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Though Hook will do whatever it takes, "good or bad" to continue their blossoming romance, he will ultimately have to determine whether "he can find a place for Emma within his heart when she's so busy trying to save the world."

Morrison added that both Emma and Hook are trying to be "better versions of themselves and vulnerable enough to be close to someone romantically," though it is more difficult in practice.

"There's a lot of trying to work out a relationship in the midst of a lot of chaos, which is funny at times and heartbreaking at times, and causes them to really figure out how this could or couldn't work," she noted.

It may not be easy for the troubled pair, but they will try to work it out.

Once Upon a Time Season 4 begins Sunday, Sept. 28 at 8 p.m. ET/PT on ABC.

Watch the Season 4 trailer for Once Upon a Time below:

Tags: Once Upon A Time television ABC