Once Upon a Time season 5
Amy Manson as Merida in Once Upon a Time season 5ABC

Rumple will have to face his biggest fear to losing the love of his life, Belle, in the upcoming chapter of Once Upon a Time season 5. Episode 6 is titled, The Bear and the Bow, which will air this Sunday at 8pm EST on ABC Network.

The official synopsis reads as follows:

In a Camelot flashback, a chance encounter with Merlin, David, Hook and Belle gives Merida new hope in her quest to save her brothers from the usurping clans of DunBroch. Unwilling to leave anything up to fate, Merida brings Belle along on a dangerous journey that culminates with an invaluable lesson in bravery. In Storybrooke, Regina, Mary Margaret and David discover the spell that would allow one of Merlin's chosen to communicate with him, but when Arthur fails to reach the missing sorcerer the heroes grow suspicious. Meanwhile, Emma commands Merida to kill Belle in hopes of forcing Mr. Gold's heroic transformation. With Merida unable to disobey Emma's orders, Gold must find the courage to fight for Belle's life or risk losing her forever, on Once Upon a Time.

Click here to watch it via live stream on ABC, or click here to watch it online on ABC's official website.

Once Upon A Time s05
Merida trains Gold in Once Upon A Time season 5ABC

Meanwhile, the latest promo of the episode shows Emma telling Merida, "You'll find her [Belle]. Put an arrow through her heart. Your job is not finished yet." Following which, Rumple turns to Belle and tells her that Merida is coming after her.

The voiceover then says, "To save this one-true love, he must face his greatest fear." After that Belle heard shouting, "Rumple run."

Actress Amy Manson previewed Merida's hidden-agenda in an interview with TV Line. Merida is ordered by Emma to kill Belle, but Manson teases that, "Merida doesn't want to do it, and what ends up happening is a formation has arisen in her own mind of how she can avenge Emma and Emma's decision, how she can get her heart back, and if there's any way that she can pull Gold into helping her."

"That's what you find out this week, that even though she's under Emma's control, Emma doesn't exactly know what's going on when she's with Gold. She has a hidden agenda, for sure," the actress revealed.