6x18 Emma & Hook #4 

ZELENA AND REGINA'S RELATIONSHIP IS TESTED BY THE BLACK FAIRY WHILE CHARMING AND SNOW DISAGREE OVER EMMA'S WEDDING PLANS ON ABC'S 'ONCE UPON A TIME'
"Where Bluebirds Fly" - In flashback, Zelena befriends a young woodcutter who has been cursed and turns to her for help finding a new heart. Zelena is forced to choose between keeping her powers and her friendship with him. Meanwhile, in Storybrooke, Zelena decides to take on the Black Fairy and put a stop to her, once and for all, against Regina's wishes, and the Charmings disagree over Emma and Hook's wedding plans, on "Once Upon a Time," SUNDAY, APRIL 23 (8:00-9:00 p.m. EDT), on The ABC Television Network.