'Once Upon a Time' season 5 spoilers: Watch Hook and Emma's date; the quest for the sword in the stone continues in episode 3

Hook (Colin O'Donoghue) vows to bring Emma (Jennifer Morrison) back to the good side in "Once Upon a Time" season 5.facebook.com/OnceABC

A new episode for "Once Upon a Time" (OUAT) will air this Sunday and it will feature more of Emma (Jennifer Morrison) and Hook's (Colin O'Donoghue) love story.

In OUAT season 5's third episode, titled "Siege Perilous," the lovers relived the old times, particularly their first date, based on the episode's sneak peek released by Entertainment Tonight.

It may appear romantic and Captain Swan fans will be thrilled at just how adorable the upcoming scenes will be, but it's likely that the Dark Swan has some hidden agenda behind it.

The preview (watch below) for the next episode has been released and other than Hook and Emma having their moments, the Captain may not be too pleased about it considering that the Dark Swan wants something and it's possible that she may even get Hook to help her get it.

The official synopsis for the next episode mentioned that the heroes will embark on a quest to save Merlin. In addition, it stated that "Emma reaches out to a conflicted Hook as she sets about her plan to draw Excalibur from the stone."

Will it mean that Hook will be the one to pull the sword out of the stone? Will love win again this time for the couple knowing that Emma is starting to fight with the Darkness inside her?

All hope is not lost for Emma, according to Morrison herself, who explained her role as the Dark One.

According to Morrison, Emma's journey is much like Rumpelstiltskin's (Robert Carlyle) when he used to have the Darkness inside him.

"Once you've agreed to surrender to the Darkness and be the Dark One, that doesn't mean that you're consumed with it immediately," the actress said in last month's interview with Entertainment Weekly.

"It means that it's within you, and now there is the struggle between what was once you and how to reconcile that with the Darkness that's also within you at this point," she added.

Fans will just have to watch how Emma will battle it out with the Darkness and if Hook's love for her can save her.

"Once Upon a Time" season 5 episode 3 will air on Sunday, Oct. 11, at 8 p.m. EST on ABC.

OUAT Season 5 episode 3 trailerYouTube/Television Promos