"Once Upon A Time" returns next week with its third episode, "Siege Perilous." The promo footage for the episode airing on Sunday asks, "Can passion survive darkness?" 

In the recently aired second episode, "The Price," viewers were given a glimpse into the mysterious events of the past six weeks in Camelot. King Arthur and Queen Guinevere threw a ball in honor of the arrival of the Storybrooke gang. Regina stepped up as a hero but could not escape her dark past. 

Back in Storybrooke, Hook employed several fairytale-proven techniques, such as true love's first kiss, to bring Emma back into the light. Unfortunately, his plans backfired and more tension developed between them. 

In the upcoming episode, Emma discovers — thanks to her Rumpelstiltstkin-voiced inner thoughts — that she needs a hero in order to pull the Excalibur from the stone. Unfortunately for the Dark Swan, she is no longer a hero. It seems that Emma is desperate and does whatever she can to get her hands on the sword. 

According to Carter Matt, there are also tough times ahead for Emma and Captain Hook. Their relationship troubles may take center stage in the upcoming episode. 

In the promo footage, Emma asks Hook to trust her. However, Hook laments that she is no longer the same person. Then, Emma asks him is he still loves her because if not, she will let him go. 

In the past seasons of the show, Hook has redeemed himself from his dark past and has started fighting with the good guys. However, now that Emma is on the dark side, he is torn. The pirate captain is still fighting hard for her, and the upcoming episodes will show if he can stay true to his alliances or if he will choose to follow Emma's dark path. 

According to executive producer Adam Horowitz, "Their relationship is a big part of the first half of the season." The obstacles they experience are part of their journeys, but unfortunately for viewers, "it's going to take the 11 episodes to get there." 

The upcoming episode will also show David and King Arthur as they embark on an "impossible quest." 

To see how these events unfold, fans need to make sure to catch "Once Upon A Time" on Sunday, Oct. 11, at 8 p.m. ET on ABC.