'Once Upon A Time season 5 spoilers, plot news: Hercules and Megara help heroes save Hook in 'Labor of Love'

The next episode of "Once Upon A Time" season 5 brings the heroes closer to Hook. Titled "Labor of Love," the upcoming installment sees Emma and the group make progress in their search for the pirate.

In the promo, Hook was shown waking up to a whole new and much more dangerous realm. He is being held prisoner by Hades along with a young lady who he helps to escape and instructs to look for Emma.

Hercules helps the heroes in saving Hook in "Once Upon A Time" season 5 episode 13ABC

This prisoner is revealed to be Megara, played by "Hannibal" star Kacey Rohl. She has spent a long time inside the dungeon but Meg's spirit does not waver. She is described as an adventurer, one who longs to "shine brightly" one day.

Megara seems to have succeeded since Emma and the team eventually found where Hook is being kept. Unfortunately, getting him out of there won't be a piece of cake. The synopsis for the "Once Upon A Time" season 5 episode says a beast is guarding the place.

This is where Hercules, played by Jonathan Whitesell, comes in. He happens to be Mary Margaret's old childhood friend who she believes is powerful enough to kill the monster. Hercules is described as a strapping young lad who believes he is destined to be the greatest hero that ever lived.

However, when Mary Margaret finds him, he isn't as heroic as she remembers. Nevertheless, she believes he still has courage in him.

"We're going to fight that three-headed beast," she tells Hercules in the "Once Upon A Time" season 5 promo. "And we're going to win," she declares.

It looks like she will be able to convince the dashing young man to fight the nightmarish guardian of the Underworld. In a promo image for "Once Upon A Time" season 5, episode 13, Hercules is seen standing alongside Emma, Regina and Mary Margaret as they enter the prison Hook is in.

"Once Upon A Time" season 5, episode 12, "Labor of Love" airs March 13 at 8 p.m. ET on ABC.