"The Black Fairy" is the nineteenth episode of the sixth season of the American fantasy drama series Once Upon a Time, which aired on April 30, 2017.
In this episode, The Black Fairy's origins and the secret that she kept from Rumplestiltskin are revealed in the present day as Gold takes Emma and Gideon inside the dream world to seek out the truth, while Regina helps Zelena adjust to a normal life without her magic.
Fiona and Malcolm bore a son on a winter's night, but soon learn from the child's fairy godmother - Tiger Lily - that as the Savior, he is prophesied to die fighting a great evil.
Finding that none have it, Fiona comes up with a new idea that requires being allowed into the sacred fairy vault, but Tiger Lily soon deduces that Fiona's plan involves combining two spells, which is against the rules, to create a curse - the Dark Curse - which will banish all of the children to a land without magic, eliminating the threat they pose to her son.
At the Pawn Shop, Gold attempts to use a scent to wake up Mother Superior, but after it fails, he steps outside and sends a newspaper box flying as Belle calms him down.
When Emma comes out to tell Gold Mother Superior is awake they go back in so they can ask her about the missing wand.
As Snow, David and Hook search for the other part of the wand, Fiona has Mother Superior as her prisoner under the mines.
Inside the dream world, Emma learns that Gold wanted her with him so she wouldn't try anything that would prevent him from finding Gideon's heart.
Thanks to Emma's advice, the three witness the flashback that shows Fiona become the Black Fairy and the revelation that Gold was destined to become the Savior.