Click your heels, “Once Upon a Time” fans! The hit ABC series is heading back to Oz to explain how Red ended up in the Underworld.

Last week Red (Meghan Ory) traveled via magical storm to get to the Underworld. In episode 18, viewers learn that prior to that she was in Oz with Mulan (Jamie Chung) looking for her wolf pack. So, how did she end up among the dead? It’s a long story involving Dorothy (Teri Reeves) and Zelena (Rebecca Mader).

A flashback reveals that Dorothy teamed up with Mulan and Red in order to find her dog Toto. Unfortunately Toto’s decision to run away was ill timed. The trio runs into Zelena while they’re in the woods and learn that she’s been banished from Storybrooke. Zelena wants Dorothy to hand over her magic slippers so she can return to her baby, but Dorothy refuses. However, Zelena has Toto. She warns Dorothy that the only way she’ll get her beloved dog back is if she gives up the slippers.

Dorothy and Red grow close as they hatch a plan to get back Toto. But Dorothy’s feelings for Red confuse her — especially after she sees Red morph into a wolf. Red is equally confused. She confides her feelings for Dorothy to Mulan, and her friend encourages her to come clean to her crush. But Dorothy’s gone when Red goes to tell her how she feels.

That’s why Red used a magic spell to go after Zelena. She knew that the wicked witch had done something to Dorothy, she just didn’t know what. She also didn’t know that Zelena was in the Underworld.

Surprisingly, Zelena is not happy to see Red in the Underworld. She knows that if the others found out what she did to Dorothy that they would never let her see her daughter again. But what exactly did she do to Dorothy? She put a sleeping curse on her!

Regina (Lana Parrilla) and Snow White (Ginnifer Goodwin) show up with Red in the nick of time to stop Zelena from clicking her heels three times with Dorothy’s magic slippers. A defeated Zelena confesses to Red that she stole Dorothy’s shoes and cursed her. Dorothy can only be reawakened by true love’s kiss. That’s devastating news for Red, who tells the others that Dorothy didn’t have anybody in Oz.

While Dorothy didn’t have anybody living who loved her, Red does remember that late Dorothy’s Auntie Em (Gina Stockdale) did love her. They seek out Auntie Em, who runs a rival diner in town. As the heroes start to explain their plan to bottle one of Auntie Em’s kisses to bring to Dorothy, Hades (Greg Germann) manages to trick Auntie Em into drinking water from the River of the Lost Souls. The water melts Auntie Em, turning her into a puddle before they can bottle her kiss to save Dorothy.

The move from Hades not only gives him brownie points with Zelena, but it also distinguishes some of the hope lingering in town. He further crushes hope by removing the magical telephone booths. That means that Snow and David (Josh Dallas) no longer have a way to communicate with their son. But David plans on changing that. Now that Red is in the Underworld with Dorothy’s slippers they can use the magic to return home. Emma (Jennifer Morrison) agrees that it’s time for her parents to go back for Neal. The only problem is that Snow’s name is on the tombstone, and no magic slippers can change that. David’s the only one that can return to their baby.

David wishes that Snow could reunite with Neal, and Hook (Colin O’Donoghue) realizes that they can change Snow’s fate. Hades gave Hook the power to carve someone’s name into the tombstones, so Hook scratches out Snow’s name and carves David’s.

Snow’s initially upset with David, but knows that being there for their baby is more important. And she also provides a support system for Red. Her old friend is still upset about not being able to wake Dorothy, but Snow tells her that she might be the solution. Snow explains to Red that she’s never seen her worry about someone so much, and Red agrees. She confides to Snow that she loves Dorothy, but doesn’t think Dorothy feels the same. Snow promises that there is only one way to find out.

Together they use the magic slippers to return to Oz. Mulan was able to find Dorothy’s body and bring her to the town square. It’s there that Red kisses Dorothy — and wakes her!

The Author’s pen allows Henry’s (Jared Gilmore) to tell the others that Dorothy’s fine and that Snow made it home to Neal. It’s a small victory, and unfortunately they don’t know that more trouble is brewing.

Zelena finally decides to cave into her feelings for Hades, and Belle (Emilie de Ravin) takes her fate into her own hands. Afraid that Hades will speed up her pregnancy in order to take her baby, Belle reveals to Gold (Robert Carlyle) that she has a plan — use a sleeping curse. If she’s under the sleeping curse then everything pauses, including her pregnancy. Gold tells her that if her plan is for him to become a good man then it’s not going to work. But Belle says she knows that. She tells Gold to make sure he returns her body to her father after he figures out a way out of his contract with Hades. Belle pricks her finger with the cursed pin before Gold can say another word.