"Once Upon A Time" season 5 premiere titled "The Dark Swan" will be back on ABC at 8pm on Sunday, 27 September. Episode 1 might revolve around the relationship between Emma (Jennifer Morrison), her son Henry Daniel Mills (Jared S Gilmore) and lover Captain Hook (Colin O'Donoghue). 

The first episode of the new season, which will be live streamed here, will pick up from where it left in season 4 with Morrison's character being the Dark One and the heroes trying to figure a way out to save her.

While the saviour of Storybrooke will have a strong bonding with her son even after she becomes the Dark One, she will have a complicated relationship with her lover in the premiere episode, teased Jennifer Morrison.

The actress revealed that Henry will be "Emma's kryptonite as Dark Swan" and he will have "the most powerful effect on keeping her from wanting to lean into the Darkness". She even said that "Hook is the next most powerful force", but her "capacity for manipulation and for selfishness" will make their relationship complicated.

"It's a complicated dance whenever Emma's dealing as the Dark Swan with Hook because her feelings are true, but her decision making is based in a bad place now. That clearly affects them, and it clearly affects whether or not he can trust her decision making," Entertainment Weekly quoted Morrison as saying.

The official synopsis of "Once Upon A Time" season 5 episode 1 titled "The Dark Swan" reads: "Immediately after becoming the Dark One, Emma disappears and the heroes must band together to save her, but first they have to find her, which will require the help of an unlikely ally."

"Meanwhile, in the Enchanted Forest, Emma struggles to resist her dark urges as she searches for Merlin in the hope that he can stop her transformation. Along the way to Camelot, she gets help from the plucky and brave warrior princess Merida, as well as King Arthur and his Knights of the Round Table."

Fans of the fairy-tale drama series can tune in to ABC at 8pm on Sunday to watch an adventure-filled season premiere of the TV show.