The fourth season of ABC's Once Upon a Time is the season of hearts, at least for Emma (Jennifer Morrison) and Hook (Colin O'Donoghue).

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After helping Hook save his heart, Emma will find that she needs help protecting her own heart in the second half of the season. Once Upon a Time co-creator Adam Horowitz recently spoke with TVLine about Emma and Hook, revealing that things have switched for the coupe.

"The tables are turned," he said, adding, "Hook, after having Emma return his heart, will now have to fight to protect Emma's heart."

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It is unclear if he means that Emma's heart will literally need protecting or if it's just a metaphorical turn of phrase, but it should be another interesting bump in the road for fans of "Captain Swan."

Things will not necessarily go smoothly for the couple, as Horowitz previously told Entertainment Tonight.

"You're going to see more challenges between the two of them as the season progresses," Horowitz revealed in early January. "There's going to be some very unique, not necessarily obstacles in their relationship, but personal obstacles that will make things interesting for the two of them."

He said that the relationship would continue developing through the second half of the season.

Once Upon a Time returns for the second half of season 4 on Sunday, March 1 at 8 p.m. ET/PT on ABC.

Watch the promo for the next episode of Once Upon a Time here:

Tags: Once Upon A Time television ABC