Okay, so I am not going back to Isa/Danella yet. So this is going to move to focus on Natasha Romanoff for a bit. Still a third person point of view.
Natasha had no problem calming her expression. But inside she was furious. Her little sister was hurt and she may not survive. And the man that hurt her was claiming that he loved her. That they were engaged. She is Isa Romanoff. Not Danella Vanira. Sure, there is not much known about her when she was a child. But she couldn't be a lost princess. Realizing that she was starting to become even more furious she took a deep breathe and walked up to Loki's holding cell.
He was pacing as if he was waiting for something or someone. He suddenly stops then smirks. "There's not many people that can sneak up on me. You are one of the few who can. There are only two others. And I believe that you think that you know one of them fairly well. I believe you call her sister."
Her ignoring the mention of Isa she spoke, "But you figured I'd come."
"After. After whatever tortures Fury can concoct you would appear as a friend, as a balm. And I would cooperate." He answered while walking as close as the cell would let him to Natasha.
"I want to know what you've done to Agent Barton."
"I would say I expanded his mind. But you and I both know, he is not the only reason you are here. You are angered at my brother for hurting your sister. And you want to know if I can do anything to make sure she lives."
Natasha, still ignoring the mentions of Isa, walks towards the cell. "And once you've won, once you're king of the mountain, what happens to his mind?"
"Is this love, Agent Romanoff?"
"Love is for children, I owe him a debt."
"Tell me." Loki said as he took a few steps back.
She sighed and began to tell him her story. "Before I worked for SHIELD, uh, Well, I made a name for myself. I have a very specific skill set. I didn't care who I used it for, or on. I got on SHIELD's radar in a bad way. Agent Barton was sent to kill me. But he made a different call. When I found my sister, she didn't want much to do with the life she had. Clint and I taught her everything she knows about being an agent and Fury employed her."
"And what will you do if I vow to spare him and save Danella?" He asked looking at her.
"Not let you out."
"No, But I like this. Your world in the balance and you bargain for two people." Loki said while laughing.
"Regimes fall every day. We tend not to weep over that. I'm Russian. Or, well, we both were."
"And what are you now?" Loki asked.
"It's really not that complicated. I got red in my ledger. I'd like to wipe it out." Natasha said while standing up again and walking towards Loki.
"Can you? Can you really wipe out that much red? Dreykov's daughter, Sao Paulo, the hospital fire, risking your sister's life so she would become like you? Barton told me everything." He said while standing back up. "Your ledger is dipping. It's gushing red. And you think that saving two people no more virtuous than yourself will change everything? This is the basest sentimentality. This is a child at prayer. Pathetic! You lie and kill in the service of lairs and killers. You pretend to be separate, to have your own code, something to make up for the horrors. But they are apart of you. And they will never go away." He struck the glass, making Natasha jump back. "I won't touch Barton, not until I make him kill you. Slowly, intimately, in every way he knows you fear. And then he'll wake just long enough to see his good work. To see that he killed you and broke Danella's spirit by taking someone that she loves away from her. And when he screams, I'll split his skull."
Out of feigned fear and disgust she turns away from Loki.
"This is my bargain, you mewling quim." He hissed.
"You're a monster." Natasha said sounding as if she was crying.
Loki chuckles. "oh, no. You brought the monster."
Looking up Natasha says, "So, Banner. That's your play."
"What?"
Natasha begins to walk away and speaks into her mic. "Loki means to unleash the Hulk. Keep Banner in the Lab. I'm on my way. Send Thor as well." She stops and looks at Loki once again. "Thank you for your cooperation. And just so you know, my sister will survive. She is a Romanoff and a Stark."
"You should know that this prison won't hold me much longer. This might as well be a wet paper bag. Either I get out myself, or Danella will help me." Loki replied with a smirk.
She turns and starts to walk towards the infirmary to check on Isa.
When she gets there, she takes Isa's hand in hers and speaks in a low whisper to her sister.
"Isa, if you can hear me, please wake up. Stark will go crazy if he doesn't have his daughter anymore. Clint would miss you too. You are like his baby sister. He loves you. So does Stark." A tear escaped, running down Natasha's cheek, it hits Isa. She barely whispers, "I love you. I don't know what I'd do without you, sister. I know that I broke the promise I made, I promised that I made that I would not let anything happen to you. I can't lose both you and Clint. But if you wake up. I promise, on my life, that I will do everything in my power to see that you are never to be hurt again." Natasha tightened her grip on her sisters hand. "But you gotta wake up Isa. Please."
She sat there for ten minutes, hoping that there would be any sign that Isa heard her. Not noticing her other hand twitch, she sighed, wiped her face and walked to the lab.