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.

"Once Upon a Time" stars Ginnifer Goodwin as Snow White/Mary Margaret, Jennifer Morrison as Emma Swan, Lana Parrilla as the Evil Queen/Regina, Josh Dallas as Prince Charming/David, Emilie de Ravin as Belle, Colin O'Donoghue as Hook, Jared S. Gilmore as Henry Mills, Rebecca Mader as the Wicked Witch/Zelena and Robert Carlyle as Rumplestiltskin/Mr. Gold.

Guest starring are Keegan Connor Tracy as Mother Superior Blue Fairy, Beverly Elliott as Granny, Giles Matthey as Gideon, Jaime Murray as Black Fairy, Alex Desert as Stanum, Austin Obiajunwa as Young Stanum, Dylan Sloane as Bully, Jorden Birch as Oz Guard #1 and Isabella Black-Thomas as Young Zelena.