A Curious Thing

"A Curious Thing" is the 63rd episode of Once Upon a Time.

Summary
While things begin to heat up between Regina and Robin Hood, Zelena threatens to kill Henry if Hook - whose lips have been cursed by her - doesn't proceed with kissing Emma, an act that would drain all of her magical powers away. Meanwhile, back in the fairytale land that was during the past year, Snow and Charming go in search of Glinda, the Good Witch of the South, to see if she can help them defeat Zelena, and the curse that will ultimately send the fairytale characters back to Storybrooke is cast... but from an unlikely source.

Trivia

 * The title card of this episode features a flying monkey that soars upward before going through the "O" of the logo in the direction of the screen.

Production

 * The title of this episode was revealed by executive producer/co-creator Adam Horowitz, via his Twitter account, on February 12, 2014.

Ratings
The episode saw a huge jump in ratings from the previous outing and won in its timeslot for the third week in a row, posting a 2.2/6 among 18-49s with 7.34 million viewers tuning in.

Reviews
The episode garnered an overwhelmingly positive reaction from critics, who praised its fast pacing, plot resolution, and emotional peaks, particularly the casting of the Dark Curse by Snow White, involving Prince Charming's sacrifice.
 * Recapping for EW, Hillary Busis was very appreciative of the episode, calling it "awesome" and writing "This is what Once should be: a fast-paced thrill ride boosted by the occasional wisecrack and only marred a tiny bit by relative implausibility.".
 * Lily Sparks, for TV.com, was also very satisfied with the episode, deeming it a "triumph" emotionally ("There were some supremely satisfying moments and a few genuine surprises.")

Gallery
Gallery of photographic stills released to promote the episode.