The characters on “Once Upon a Time” have been doing their best to maintain their hope while in the Underworld, but that may change in Sunday’s episode. Star Jennifer Morrison revealed to International Business Times that Emma and Hook’s journey won’t be an easy one.

Episode 20 will find Hades (Greg Germann) turning to the Storybrooke heroes for help after Gold (Robert Carlyle) and Pan (Robbie Kay) kidnap Zelena (Rebecca Mader). Regina (Lana Parrilla) is prepared to do whatever it takes to get back her sister. However, it’s Emma (Jennifer Morrison) who Hades wants to aid him. He promises to remove the names he carved onto the tombstones if Emma rescues Zelena. But there’s a catch — Hook’s life is not part of the deal.

“Hook and I think that we have a solution to be able to bring him back to Storybrooke,” Morrison told IBT. “So we’re going to go on this journey together to try to achieve that. And obviously nothing ever goes as planned and nothing’s ever easy. And nothing is ever quite what it seems.”

It’s an adventure that will certainly show off Emma’s strength, something that some fans have been complaining has been lacking in recent episodes.

“There have been fans at times who have said things like, ‘Oh, well, she’s not tougher anymore. She’s not strong anymore.’ Do you know how strong you have to be to be vulnerable? I think you have to be even stronger to be vulnerable than to be defensive. And so I see it as an evolution of her strength for her to feel that she has it in her to be this vulnerable, to be this open, to risk getting hurt. I think that takes an incredible amount of strength.”

Morrison’s character will certainly show her strength tonight. Clips from episode 20 tease that it will be an emotional ride.