Mary Margaret will get a slap in the face in the upcoming episode of "Once Upon a Time". David finally agrees to tell Kathryn about his relationship with Mary Margaret and put an end to his loveless marriage, but it's Regina who may first reveal his affair to his wife. Shocked by the news, Kathryn comes to see Mary and give her the unexpected slap.
Meanwhile, in the fairytale land, runaway groom Prince Charming agrees to aid Abigail to recover something precious that was lost to her while he is in search for Snow White. In the dangerous mission, Prince Charming must face a big tempation, but one mistake could result in a deadly end for him.
"What Happened to Frederick" will air next Sunday, February 19 at 8/7c on ABC.