The Stable Boy is another classic episode in the first season of Once Upon a Time next to That Still Small Voice which did a great job exploring the back-story of Jiminy Cricket/Archie in Storybrooke. This does a great job in giving a really sympathetic back-story to how the Evil Queen came to be. She fell in love with a stable boy named Daniel who works with her mother, Cora Mills, and father, Henry Mills before she met the young Snow White.
This episode is beyond flawless and there's no problem I have with it. The story and script are very well-written and excels in the emotional moments where Cora kills Daniel, thus breaking Regina's heart and it made me feel sad. Also, it does a fine job continuing where the Mary Margaret subplot left off. The pacing's much tighter, the directing's more sharper, the music score from Mark Isham is fantastic and excels in the episode's emotional moments, and the performances are still solid especially Lana Parrilla who shines with her heartbreaking performance when Daniel dies. So, overall, another episode that is the best of the entire season. :)