The Miller's Daughter
Once Upon a Time Season 2 Episode 16 (03/10/13)
-A young Cora is the miller's daughter. She's treated badly by Princess Eva and the king forces her to her knees in public. When she later claims she can spin straw into gold, the King tells her if she does it she can marry the Prince but if she can't he will kill her.
-Rumplestiltskin appears. He makes her a deal. He will teach her the magic to turn straw into gold if she promises him her first child. She agrees.
-Later she and Rumple fall in love and Rumple changes their deal. He'll allow her to rip the King's heart out and she'll run off with him and have his child. But Cora lets the King live so she can marry the prince and she leaves Rumple, breaking his heart.
-Emma, Neal, and Henry get Rumplestiltskin back to Storybrooke. Henry goes off with Ruby while Mary Margaret and David join in to battle Regina and Cora.
-Rumple guides Emma in using magic to cast a protection spell. Then he tells Mary Margaret the only way to defeat Cora is to use the magic candle. It will save Rumple but Cora will die if they can find her heart and put it back inside her.
-While Cora breaks through the protection spell, Mary Margaret finds her heart in Regina's vault. Regina finds her and Mary Margaret convinces her that the reason she's never felt her mother loved her is because Cora hasn't had her heart.
-Cora tells Rumple he was her one true love, that she had to remove her own heart to be able to leave him and attain true power.
-Regina inserts Cora's heart. Cora tells Regina she know realizes that loving her would have been enough for her. Then she collapses and dies as Mary Margaret runs in having changed her mind. Regina realizes that Mary Margaret caused the death of her mother.