Devil's Due

"Devil's Due" is the 102nd episode of Once Upon a Time.

Summary
When Hook fails to choose which three of his rescuers will have to remain in the Underworld, his captivity takes a dark turn as Hades threatens to condemn him to the River of Lost Souls. Meanwhile, Gold is suddenly eager to help Emma and the others find the deceased pirate so that he can return home to Belle, but in order to do so he must first find his late wife Milah somewhere in the town and ask for her help. Concurrently, in the fairytale land that was, Rumple and Milah face a life-or-death crisis concerning their son Baelfire that forces the former to make a deal that will haunt him forever.

Plot
"Previously on Once Upon a Time..."

In the the Underworld's graveyard, Emma and the others stand before a holographic image of Hook, with the blonde exclaiming that they are there to find him; she proceeds to ask where he is. Hook awakens in a troubling state, with Megara revealing they are trapped in an underground prison. Belle is taken aback by the news of her husband heading for the Underworld, but he assures he'll only be gone for a day. The beauty kisses her true love, telling him to come back to her, and he replies that he always does. Peter Pan comes across Rumple in the Underworld's version of the pawn shop, and fails to convince his son to help him swap places with one of the others who journeyed to the new realm so that he himself can return to the land of the living. In order to punish Hook, Hades forces him to chisel the name of one of his friends into a gravestone so they cannot leave the Underworld, each time they help a soul move on.

Teaser
Down in Hades' lair, the beaten and bloody Captain Hook remains in silence, for he is refusing to cooperate with the Lord of the Underworld's wishes. "Oh come on," Hades exclaims, mockingly, "all you need to do is chose three of your friends." He simply wishes for the Pirate to carve their names. Hook looks up, not happy, and so Hades continues teasing even more, asking what's wrong. He wonders if it's the chisel and it being two unwieldy for the one-handed; or writer's block. The Pirate drops the chisel, showing he's not in the mood for Hades' games, and proceeds to exclaim he's not doing it. A look of frustration comes across Hades' face, and to which he replies to the Pirate, "I must say, I'm not angry. I'm disappointed," however, he approaches Hook's face and whispers in his ear, "And on second thought, I'm angry." With that, the Lord of the Underworld exclaims that it's off to solitary for the Pirate, and proceeds to grab a hand full of the beaten former Captain's hair, resulting in several yelps of pain. As Hades drags a hobbling Hook around, he is told to listen carefully, for they look down into a green river: the River of Lost Souls. "Touch it, and it will make you lost," Hades says, continuing that it will reduce one to a "mindless, tormented husk". With that, the Lord of the Underworld leaves the Pirate with one final request, that being, "So please, keep all arms and hand inside the boat." The two look out, with Hook fearing his fate, and Hades reveling in what that will be. ONCE UPON A TIME

Trivia

 * The title card of this episode features Hook being suspended by chains amid the red skies of the Underworld.
 * Although credited, Rebecca Mader (Zelena/Wicked Witch) is absent from the episode.
 * Jane Espenson's favorite scene of the episode was that of Rumplestiltskin and Milah on the boat in the Underworld, awaiting Emma's return with Hook.

Production

 * The title of this episode was officially confirmed by executive producer/co-creator Adam Horowitz, via his Twitter account, on November 26, 2015.
 * This episode marks the twenty-first writing credit for Jane Espenson, as well as the third directing credit for Alrick Riley.

Gallery
Gallery of photographic stills released to promote the episode.