EMMA CONTINUES HER SEARCH FOR EVIDENCE TO PROVE MARY MARGARET'S INNOCENCE IN KATHRYN'S MURDER, AND REGINA MUST CHOOSE BETWEEN BETROTHVING A ROYAL OR BETRAYING HER MOTHER AND MARRYING A COMMONER, ON ABC'S "ONCE UPON A TIME"

Barbara Hershey Guest Stars as Fairytale Land Regina's Mother, Cora

Alan Dale ("Lost") Guest Stars as District Attorney Albert Spencer/King George

Richard Schiff ("The West Wing") Guest Stars as King Leopold

"The Stable Boy" - Emma continues her exhaustive search for evidence that will prove Mary Margaret's innocence in the murder of David's wife, Kathryn. Meanwhile, in the fairytale land that was and before evil blackened her soul, Regina must choose between betraying her mother, Cora (Barbara Hershey), and marrying for true love, or betrothing royalty and living a regal - but loveless - life; and the event that caused the Evil Queen to loathe Snow White is revealed, on "Once Upon a Time," SUNDAY, APRIL 1 (8:00-9:01 p.m., ET) on the ABC Television Network.

"Once Upon a Time" stars Ginnifer Goodwin as Snow White/Mary Margaret, Jennifer Morrison as Emma Swan, Robert Carlyle as Rumplestiltskin/Mr. Gold, Lana Parrilla as Evil Queen/Regina, Josh Dallas as Prince Charming/David, Eion Bailey as August, Jared Gilmore as Henry Mills and Raphael Sbarge as Jiminy Cricket/Archie Hopper.

Guest starring are Anastasia Griffith as Kathryn/Abigail, Meghan Ory as Ruby/Red, Tony Perez as valet/father, Giancarlo Esposito as Sidney/The Mirror, Alan Dale as Albert Spencer/King George, Barbara Hershey as Cora, Noah Bean as Daniel/stable boy, Richard Schiff as King Leopold and Bailee Madison as young Snow White.

"The Stable Boy" was written by Edward Kitsis & Adam Horowitz and directed by Dean White.

"Once Upon a Time" is broadcast in 720 Progressive (720P), ABC's selected HDTV format with a 5.1 channel surround sound. A TV parental guideline will be assigned closer to the airdate.

For more information on "Once Upon a Time," visit ABC.com/Once