"Regina, NO!" The cry that emanated from Emma was visceral. The sight of Regina clutching her mother's heart in her hand was too much to bear. The tears fell of their own volition while she prayed for divine intervention to give her the right words to talk the Evil Queen down from her moment of vengeance.

Lucky for Emma, Regina's gaze turned toward her briefly, though she was terrified by the look of fury mixed with pleasure that graced the brunette's facial features. The level of darkness it contained was simply not the Regina Mills she had come to know. She found herself begging, "Regina, please don't do this."

"Go home, Emma. You shouldn't be here. This isn't about you," Regina glared, though she let up a bit on squeezing Mary Margaret's heart. She had her own gripes with Emma, not the least of which included taking her son to New York without getting permission, but that paled in comparison with what Mary Margaret had done.

Mary Margaret didn't want Emma there either. She'd offered her heart to Regina of her own free will. She wanted to die, but she didn't want Emma to witness it. The agony of having her heart squeezed was what she deserved. She cried out in pain, "Emma, do as she says."

"I'm not going anywhere! She's my mother, Regina. I only just got her back. Surely you can understand that?" Emma continued to plead her case. She knew that any chance of success was microscopic, but she had to try. She was the only one in Storybrooke who had experienced the type of loneliness and anger at the hand the world dealt her that was clearly driving Regina now.

"She tricked me into killing my own mother," Regina was unwavering, so sure in her right to vengeance that Emma's words were only a glancing blow. The love she found in her mother's dying eyes still haunted her. Her mother had always said that love was weakness, and her own desire for her mother's love had been manipulated by her worst enemy into killing the one person who had always been there for her, wanting only the best for her little girl.

"Which is absolutely unforgivable, and you have every right to be angry," Emma empathized. She knew this wasn't the time to remind Regina how Cora had tried to kill them all or how Cora had chosen power over her own daughter's life.

"I do?" Regina's look of surprise quickly turned to that of suspicion. Not that she really had a reason to distrust Emma, but she also didn't really have a reason to trust her either.

Emma saw the split second break in Regina's armor and ran with it, "Yes, you do. I'm not asking you to stop for her sake; I'm asking you to stop for mine. Because you owe me. For the 28 years I spent thinking my parents had abandoned me by the side of the road."

"You were better off," Regina scoffed. Besides, she hadn't made the decision to send Emma through the wardrobe motherless; that had been Snow's idea. Still, the blonde was getting to her more than she would like to admit.

"Was I? Would you have been better off without your mother?" Emma wanted to take back her words as soon as she'd said them. Some arguments were below the belt no matter what the reason. She didn't know the exact details of Cora's relationship with Regina, but she'd been through enough foster family situations to recognize when something was horribly amiss.

Mary Margaret's level of remorse only intensified. She knew Cora wasn't the best mother a girl could have, but the Queen of Hearts was still Regina's mother, and no one deserved to be manipulated into killing their own mother—no matter what their sins. She tried once again to get her daughter's attention, "Emma!"

Both Emma and Regina ignored the schoolteacher's pleas as they were too busy staring each other down. Standing at her full height, Regina drew the line in the sand, "You do NOT get to talk about my mother."

Emma tried a new tactic, "What about Henry, then? Can you honestly say he would have been better off without you, caring about him, loving him? He's a wonderful little boy, Regina, and that's all because of you."

"Says the woman who took him from me," Regina remembered all too well the words Emma had shouted at her: how Henry was Emma's son, not hers, and how Regina would never change. The two of them always had knock-down, drag out fights, but she'd never forget the look on Henry's face as she watched Emma poison him against her from afar.

"That was a huge misunderstanding. I didn't want to believe you had killed Archie, but that stupid dreamcatcher, and I was too embarrassed afterwards to apologize for all the horrible things I said. This magic stuff is all new to me," Emma tried desperately to explain the inexplicable.

Regina was unconvinced. She needed something more, even though she had no idea what. She challenged, "Give me one good reason why I should put this heart back in your mother's chest."

Mary Margaret was aghast. This wasn't how she'd imagined this scene going down, not by a long shot. Emma wasn't supposed to save her. Mary Margaret pleaded, "Regina, please don't."

"Because I…love you," Emma sobbed uncontrollably.

"What?!"

"I love you," Emma repeated, more forcefully this time. She hadn't planned to make such an admission, but once the words were spoken, she couldn't lie about her feelings anymore. She needed Regina to come out of the darkness before she herself was drawn to it.

Regina was cold. She'd fallen for a similar trick once already, and she was no fool. How dare Emma of all people manipulate her like this? She responded, "Do you see this black spot on your mother's heart? Do you know what caused it? She took the love I felt for my mother and twisted it for her own ends. She told me if I put the heart back in my mother's chest that my mother would finally love me back. And now, her daughter is trying the same tactic. Emma, I thought better of you."

"I'm not lying! Regina, this isn't some kind of trick, I swear. Is it so hard to believe I could have feelings for you? After all we've been through? I fought a dragon for you. We opened a portal to a parallel universe together. Regina, look at me. Not the daughter of Snow White and Prince Charming, look at me, Emma. The woman with seven addresses in the last ten years, the woman who keeps everyone at arm's length because she expects to get hurt every single time. The woman who walked away from her own son until you challenged me to stay. You of all people should know how hard this is for me," Emma stepped closer to Regina with every word she spoke until they were nose to nose. Her eyes searched the other woman's gaze for a sign that she was getting through.

Mary Margaret was flabbergasted, "You love her? After everything she's done?"

Making a split second decision, Regina plunged Mary Margaret's heart back into her chest. She could always change her mind later, she reasoned. Who was she kidding? She wasn't going to change her mind later. She didn't need vengeance; she needed love. She needed the strong arms that were encircling her in a protective hold. She needed the tenderness of the kiss placed on her cheek, and somehow, for a moment, she felt less broken. Regina whispered, soft enough that only Emma would hear, "I love you too."