“Once Upon a Time” is returning to ABC Sunday night after being on hiatus since early December. The upcoming installment not only marks the second half of Season 5, but also celebrates a big milestone: the show’s 100th episode. But before fans dive into the drama of the Underworld, we’ve got a brief refresher on what happened in episode 11, the winter finale.

An Important Flashback

The winter finale kicked off with a flashback to when Hook (Colin O’Donoghue) was just a young boy. It’s revealed that Hook’s father not only abandoned him and his brother when they were young, but he traded them for a boat in order to make a clean escape after stealing something. This moment helped shape Hook into the pirate he became. 

Storybrooke’s Latest Problem

Thanks to Hook, the Dark Ones have now taken over the town. They mark some of the heroes, which means that when the moon rises, their souls will be sucked into the Underworld. While the Storybrooke residents have faced their fair share of danger, everyone seems to accept their grim fate — except for Emma (Jennifer Morrison).

Emma And Regina’s Plan

As Mary Margaret (Ginnifer Goodwin) and others gather to spend their final moments with family, Emma seeks out Regina (Lana Parrilla). She’s got a plan to stop the Dark Ones, but it’s not a plan that Regina likes. Emma wants to contain all the darkness and have Regina use Excalibur on her. Regina’s reluctant but ultimately agrees to help.

Gold’s Own Plans

Gold (Robert Carlyle) is the one who encourages everyone to be with their loved ones, yet he sends his away. He tricks Belle (Emilie de Ravin) into leaving town, using some of his last magic to prevent her from being cursed.

Goodbye, Zelena

Zelena (Rebecca Mader) is a bad seed and never going to change. Unhappy with her custody arrangement with Robin (Sean Maguire) regarding their daughter, Zelena steals her and threatens to raise her to be evil. Regina has no plans on letting her half-sister take away Robin’s daughter though. She uses an old wand to summon a twister to bring Zelena back to Oz. However, Zelena warns Regina that she hasn’t seen the last of her.

Hook’s Betrayal

Dark Hook figures out what Emma has up her sleeves and tricks her into handing Excalibur over to him. With the powerful sword in his possession, Hook and Nimue can complete the transition from the Underworld to the real world. However, Regina has one last idea to stop Hook. She reminds him about the man he wanted to be.

Another Flashback

Another flashback shows Hook in the Enchanted Forest with Regina when she was known as the Evil Queen. Regina wants Hook to kill her mother in exchange for transporting him to a world where he could kill “the crocodile. But she wants to be certain that he can go through with it. To test him, she sends him to a bar and tells him that there is a man inside he needs to kill. Hook quickly discovers that the man in question is his father.

Like Hook, his father is immortal, so it doesn’t look like he aged. However, he’s certainly changed. When he figures out who Hook really is, he explains that a woman changed his life. He cries and apologizes to his son, causing Hook to have a change of heart about killing him. Hook even offers to fake his father’s death to allow him to start new again somewhere else. But Hook changes his mind when his father reveals that he has a new son, a child named Liam. Upset that his dad named his new son after his late brother, Hook decides to go through with killing him. But his dad’s last words to him are “you can change.”

A New Hook

The memory triggers something in Hook, causing him to change his mind last minute about helping the Dark Ones. Unfortunately it’s already too late though. The boat has arrived to take the souls from Storybrooke to the Underworld. But Hook remembers Emma’s plan and decides to be the hero he always wanted to be. He uses Excalibur to gather all of the darkness, and makes Emma plunge the sword into his chest. The two kiss and say one last “I love you” before a teary eyed Emma stabs Hook.

Emma’s plan works and Excalibur disintegrates after she uses the sword on Hook. She’s rid of the magic that made her the Dark One, but the act kills Hook.

A Twist

Belle returns to Storybrooke after learning what’s happened. She kisses Gold and rekindles her relationship with him after learning how selfless he could be. But what Belle doesn’t know is that Gold is selfish, not selfless. Emma quickly figures out that Gold tricked all of them. He was able to swap out Excalibur after gathering all the magic of the Dark Ones into the sword. That means that Hook didn’t die a hero by taking all of the darkness into the Underworld. Gold is now more powerful than ever before.

Emma threatens to tell Belle the truth unless Gold helps her. But what exactly does Emma want? She wants Gold to take her into the Underworld to rescue Hook. Emma knows that you need to trade a life, but she has her own plan — share a heart with Hook.

Once Upon a Time 2 Gold (Robert Carlyle) tricked everyone in the "Once Upon a Time" Season 5 winter finale. Photo: ABC

“Once Upon a Time” fans can find out what happens next when episode 12, the midseason premiere, airs on ABC on Sunday, March 6, at 8 p.m. EST.