'Once Upon a Time' opened with the Black Fairy threatening Zelena and her daughter Robin. Emma began planning her wedding to Hook (Killian). In the previous episode, Regina broke the curse on Prince Charming and Snow White by getting the help of the townspeople to share the curse. Emma brought Hook back from Neverland.

Snow White suggests having the wedding at Grannie's. Killian suggests the Jolly Rodger. Prince Charming suggests that they look for a new location. After Prince Charming and Snow White argue over what's right, Emma suggests they postpone the wedding until after the final battle.

Zelena tries to eliminate the Black Fairy

After the Black Fairy visits Zelena and Robin, Zelena decides to leave Robin with Belle while she pays the Black Fairy a visit. In a flashback as the Wicked Witch, Zelena receives a visit from the woodcutter she had previously helped when she was a girl. He has been cursed by the Witch of the North because he cut down a tree. He needs a new heart, and the only heart that will save him is the Crimson Heart. She refuses until he challenges her. To prove her power, she goes to retrieve the heart.

After Regina discovers that Zelena has gone after the Black Fairy, she goes in pursuit of her. They have a confrontation and fight. The cave they are in begins to collapse after Regina throws Zelena against a wall.

While The Wicked Witch and the Woodcutter walk through the woods on the way to retrieve the Crimson Heart, Zelena and Regina discover a vein of the fairy crystals in the caves.

What do they mean? Zelena attempts to destroy the Black Fairy, but it's a trap. The Black Fairy and Gideon use Zelena's magic to weaponize the fairy crystals and turn them into dark magic.The crystals will be used to start the final battle.

The Wicked Witch finds the Crimson Heart

The Woodcutter and the Wicked Witch fight the guardian of the Crimson Heart, a lion. After defeating the lion, they finally find the heart. As the Wicked Witch tries to use the heart, she discovers that the heart is draining her magic. She leaves the Woodcutter as he becomes the Tin Man.

In Storybrooke, Zelena discovers that they may be able to destroy the magic in the crystals if Zelena destroys her magic as the Wicked Witch. Zelena retrieves the Crimson Heart and uses it to destroy her magic.

Regina, Emma, and Zelena discover they can wake the Blue Fairy. They destroy the Black Fairy's magic and come one step closer to waking the Blue Fairy, who knows the Black Fairy's secret, why she really gave up Rumplestiltskin.