THE FATE OF STORYBROOKE HANGS IN THE BALANCE WHEN EMMA'S AND HOOK'S RELATIONSHIP IS TESTED AS NEVER BEFORE, ON ABC'S "ONCE UPON A TIME"

Elliot Knight Guest Stars as Merlin, Amy Manson as Merida, Sinqua Walls as Lancelot, Liam Garrigan as King Arthur and Joana Metrass as Guinevere

"Broken Heart" - In a Camelot flashback, Hook becomes a Dark One and his lust for revenge against Rumplestiltskin is reignited. When Emma and Hook disagree about their best course of action, the final pieces of the puzzle are revealed as events in Camelot catch up to the present and we witness a charged confrontation between the forces of light and dark that sends our heroes on a collision course with destiny. Meanwhile, in Storybrooke, Hook's centuries old lust for revenge against Gold puts both of their fates in jeopardy while Emma's love faces the ultimate test as she tries to convince Hook to turn away from the darkness before she, Mary Margaret, David and Regina embark on a new mission as an unsuspected evil is released, on "Once Upon a Time," SUNDAY, NOVEMBER 29 (8:00-9:00 p.m., EST) 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, Sean Maguire as Robin Hood, Rebecca Mader as the Wicked Witch/Zelena and Robert Carlyle as Rumplestiltskin/Mr. Gold.

Guest stars include Lee Arenberg as Leroy/Grumpy, Beverley Elliott as Granny, Amy Manson as Merida, Elliot Knight as Merlin, Liam Garrigan as King Arthur, Joana Metrass as Guinevere, Sinqua Walls as Lancelot, Caroline Ford as Nimue, David-Paul Grove as Doc, Michael Coleman as Happy and Ingrid Torrance as Severe Nurse.