A source close to the situation explained:
Our beloved Snow White (Ginnifer Goodwin) entered an inky-black hole of EVIL during Sunday night's Once Upon A Time when she (SPOILER ALERT!!!) CURSED Cora's heart before Regina put it back into her mother's body…
Thus KILLING Regina's evil-witch mamma! And, obviously, Regina be PISSED.
Plus, as any person who is informed in the ways of magic should know, Snow's gotsta PAY the universal fee that comes from using a spell in such a devious manner, and it seems Regina might just get her vengeance in next week's episode, titled Welcome to Storybrooke!
Protect your heart if you don't want it to get RIPPED from your body and prrreeeessss plllaaaayyy (above)!
Awww we feel for Regina, we really do!
She had craptastic childhood watched over by her dastardly Mommy Cora — who then KILLED her daughter's one true love — and just when Regina FINALLY feels a connection to her parent, Snow straight up MURDERS Cora!
No wonder she's so ANGRY all the time! We only hope that Regina doesn't sink back into the same darkness that Snow is currently experiencing, AND that Snow gets her sh*t together and stops acting so nefarious-like.