The next day comes a lot quicker than she likes and she's unsure what to expect. Loki catches her just outside the tower, a risky move despite his disguise, and leads her to an abandoned building a few blocks down. It's far away enough, she notes, without being too far for comfort. She doesn't talk on the way and lets him talk once they stop.
Loki first teaches her the basics of magic knowledge. Not every spell requires words and some need a different energy to work in the first place. He explains a lot of theory and examples it with practiced magic so it's easier for her to understand. She's a fairly quick learner and doesn't need very long to understand what he's telling her. That she can see with her own eyes what he tries to say helps.
The ones she's most interested in are the healing spells and anything that can hide her from sight but he tells her those are much too difficult to master for a beginner such as herself. Instead, he teaches her how to find and focus the energy she needs to wield magic. It's a lot like meditating and she welcomes the quiet required. There's no guarantee she has it but Loki trusts his instincts and feels a spark emanating from her. He's right. The God smiles, partly because the face she makes is almost cute and he likes the sight. She looks surprised and pleased all the same.
It's four hours later that he tells her they're done for the day. She has proven to be an excellent and fast learner. Her magical spark still isn't under any kind of control but he knows how to work on that and he has little doubt that she will try by herself. Natasha may not be fully convinced yet but her curiosity keeps her interested enough to want to be good at it. If only to be able to keep up with him.
It's despite her better judgement that she sits on her carpet later that night to focus on everything Loki has told her and attempt to keep getting that spark to appear again. It's been faint in the empty building but she has felt it and the sooner she gets the hang of summoning and controlling it, the sooner he'll teach her what she wants to know. And maybe how to beat him with it. It takes her all night to summon a spark she can hold for more than five minutes. Nevertheless, it's a victory and she's proud of herself for it.
She meets him every day to train. Every day she gets a little better, is a little more in control of that still unusual energy inside of her.
A week later he trusts her to try a first real spell. It's simple enough; a spell that he's learned as a small child. It doesn't require a lot of energy but still enough concentration to be challenging for a first attempt. He summons a flower out of thin air and shows it to her. Small things like these are easy to produce but larger items or more complicated things are better taken from an already existing place and transported to where one wishes them to be.
Loki explains how to do it and it takes her a few tries before she eventually manages. Her flower isn't as big as his and much simpler in shape and design but it is a success nonetheless.
"Not bad."
He assures her the rest of the Avengers, minus Thor who grew up surrounded by magic of all sorts, won't be able to tell that she's capable of using it. Regardless of how small the spells she uses or practices are or how big they'll get later. She's free to train inside the tower as long as she stays away from Thor while and after doing it. He's not very good at sensing magic but he's known it all his life and Loki is well aware that he would notice eventually. He may be dense at times but Thor paid attention.
Natasha grows less hateful of him the more time they spend together. She thinks it's the magic, he doesn't comment.
The more she trains, the more accustomed she gets to magic. That includes her sensitivity towards it rising as well as all effect of any magic being felt stronger than before. It helps her learn but it also turns out to be quite distracting at times. Especially when Loki shows her practical use of any spells.
He hasn't anticipated the pull becoming so unbearable. He has known it's likely to happen since she makes so much progress so quickly but he doesn't like it very much. She's mortal. And she still hates him. He's not confident that it won't distract him.
"That is enough for today." He says softly.
Natasha is disappointed and it shows. She's just starting to get better. He's gone again in the blink of an eye, before she even has the time to say anything in return, and she decides she hates it when he does that.
She heads back to the tower where Clint is already waiting for her. She's been behaving odd these past days and he's worried.
"Hey."
"Hey. What's up?"
"I was gonna ask you the same question. You've been pretty out of it lately, and I don't just mean when we're sparring."
She smiles at him and they go inside, then make their way up to the suite at the top of the building to talk and maybe have a drink or two. She has expected this to come up eventually and is almost surprised that it's taken him so long. They sit by the bar and Natasha prepares them a couple of drinks.
"I'm fine. Just a bit preoccupied these days."
"I barely even see you anymore. You're never here. Less so than before."
"I know, I'm sorry. I'm busy. Trying to clear my head, you know?"
"Did something happen?"
She shakes her head and he sighs. Clint doesn't believe her. He knows this face but there's nothing he can do if she doesn't want him to know. Obviously, she doesn't care to share. It's nothing he isn't used to but he wishes she would trust him more with things like these.
"Alright.."
"Clint, don't worry. Seriously, I'm fine."
"If you're sure. Just remember I'm here if you need me. The others too."
"I know."
At that, he smiles and they enjoy their drinks together. Natasha catches up with his latest mission and misses going on her own. Hopefully Fury would have something for her soon because she needs the distraction and she wants to go back to work.
She gets the call from Fury the next day and meets him for a mission briefing not an hour later. A simple information retrieval but she likes those and it's the perfect thing to get her back in after three weeks of holidays she never wanted. She misses her usual meeting with Loki while she's reading over the files but she doesn't give it any thought. She's back to work now and it finally gives her something else to concentrate on than Loki. Natasha is back in her actual element.
Loki isn't happy when she doesn't show up to meet him and is nowhere to be found. He decides to wait for her return in her room, unseen and undisturbed. It's odd, to feel magic other than his own here but he is strangely pleased by her efforts.
By the time she finally comes back, almost three days have passed and he's sat them out on her couch. She's exhausted and a little beaten and she really doesn't want to deal with Loki right now. He may be invisible but she knows he's there. She can feel him close.
"JARVIS, please."
The AI knows what she wants and doesn't need to ask about it. She does this often. Natasha likes her time alone, especially after a mission so she can unwind and deal with everything and anything that may have happened.
"Of course, Miss Romanoff."
She cracks a smile for nobody to see drops her things by the door.
"What happened?"
He drops the spell that's kept him hidden for days and the genuine worry on his face catches her off guard. She knows she looks worse for wear but, really, she's fine. It's just superficial cuts and bruises, plus a wound from a bullet that's grazed her. Her attackers are doing a lot worse than her.
"They didn't like me stealing their intel."
"You're hurt."
"This is nothing." She says and then grins, pleased with herself, "You should see the other guys."
"Undoubtedly. Your mission was a success then?"
"Yes."
"At least you didn't stand me up for nothing." He mumbles.
She wants to laugh. Is he seriously pouting? She drops on the couch next to him and opens her palm up, producing a more complicated flower than what he's seen her do before. He stops pouting like a child and smirks instead. She's gotten better while out on a mission. He's impressed.
"When did you manage this?"
"Yesterday."
"During your mission."
She shakes her head and smiles, twirling the flower between her fingers. "My time off it."
"You are a better pupil than I had even hoped."
"You're not half bad a teacher either."
He watches her in silence and she stills her movements when he doesn't say anything.
"You feel it, do you not?"
His question is asked so quietly she almost misses it. Natasha doesn't ask what he means, she knows. She's felt that odd pull for a while now. It's gotten a lot stronger since her skill has improved so she knows there's some magic to it. Probably because her sensitivity is higher now than it used to be. She doesn't think it's his magic though. He seems confused about it too.
"Is that what you were talking about?"
"Yes. It is not easy to ignore, is it? The stronger your magic becomes, the more I feel it. And you are merely at the beginning of learning."
"That's why you cut the sessions short."
"Yes. It becomes unbearable."
"And it's going to get worse. But you still want to teach me."
"You have extraordinary talent, Natasha. It would be a waste to stop now."
"You're an odd one."
He chuckles but can't find it in himself to disagree. She's not wrong. Since teaching her, he has grown to truly believe that they are made for each other. The idea doesn't appal him as much as he thought it would at first. He's used it to sway her, knowing it would likely add towards the opposite instead. But now he believes it himself. Now it is possible to sway her to do the same. After all, she is hardly an ordinary mortal.
"Does it bother you?"
Natasha watches him and thinks her answer over. She's not sure she wants him to know but he has been surprisingly honest with her.
"Not the way it should."
"I would like to try something." He says suddenly.
It's not that she trusts him – she'll deny it to anyone that implies – but she nods without much of a second thought. He's not going to hurt her so she's not overly concerned about what it is he wants to try.
Loki stands up and takes in the injuries he can see on her once more. He takes note of each and then reaches out to touch her cheek where a cut is running down her skin. She doesn't flinch at the contact but she is curious. He mumbles under his breath and while she can't make out most words, she recognizes a few from when he's explained spells to her. A welcoming warmth spreads across her face as the spell works to repair the damage done and it takes a lot out of her to not close her eyes and enjoy the feeling. Instead, she focuses on how concentrated he looks. It's a strange feeling but not a painful one like she's expected it to be. Loki continues the spell at each wound he finds, careful to avoid older scars on the way. Those he won't touch. They're important. He stops at the injury on her leg and looks up at her when it's fully healed.
She can't explain the sudden feel of need for him that runs through her and she wouldn't be able to recall it later either. She feels both their magic spike and he pulls away when it crawls onto his skin.
"What did you do?"
"A healing spell." He starts, "It's as I thought… Our magic is even more in tune with each other's now. Yours will be more powerful. I am uncertain if it affects mine the same way."
She wants to ask if that is the reason she feels the overwhelming need to touch him suddenly. The pull has just reached a point where she finds it almost impossible to ignore it. She stills fights to though.
"It hurts a little, normally. A little sting barely noticeable for simple injuries like yours. What did you feel?"
"Warmth." Natasha replies right away.
He's certain now that she is his weakness. Sharing his magic with her the way he just has makes them – or at least her – stronger but ultimately weaker should something grave happen to one. If she feels like fighting him, he will hurt himself fighting her back. Perhaps this has been a mistake. He decides that it doesn't matter.
"Do you trust me?"
"No."
Loki spots the lie right away and she knows it but nobody can tell her she agreed to it because she hasn't. That she trusts him at all should really bother her but she feels a much stronger kinship with him than most of the Avengers. She won't tell him that though.
He stands and she followed his example. He takes her hand and puts it on his chest, resting it against his shirt. Natasha looks up at him with a frown, wondering what it is he is trying to do.
"Do you think me a monster?"
"You do."
It's a clear evasion but Loki gives her a smile and doesn't push for a real answer.
"Close your eyes and concentrate on me. Just me. Ignore everything else."
She does as he asks and shuts her eyes. She focuses on him and it doesn't take long before she feels the energy around her shift. Her muscles spasm lightly but she keeps her eyes closed until he tells her to pull away. When she looks at him again, he's blue with foreign markings all over his body and eyes so red they're almost terrifying.
"Thor told you about my true origins. This is what I look like without Odin's glamor on me."
She reaches out to touch him but the air around him is so cold she thinks better of it. It's likely going to hurt her if she does. His expression tells her she's right with her assumption.
"Jotun."
Not Frostgiant, he notes. She's not afraid, he also notes.
"Why?"
"I cannot take it off myself unless I am touched by extreme cold, thanks to Odin. I thought perhaps with your magic I could… I thought perhaps if you saw the monster that I am by nature, I would be able to tell what you really think."
She frowns. That's not it. Natasha shakes her head and his brows twitch. It takes her two more seconds to figure him out. For somebody so skilled in lying and hiding, he couldn't be more obvious now.
"You wanted to see if I would still accept you if I saw what truly lies underneath." She lifts her hand to his face but keeps away enough not to touch. His breath freezes against her fingertips. "Because if somebody else could, then maybe you can accept yourself too."
The blue vanishes slowly and when she deems it safe to touch him, she puts her hand back on his chest, closer to the skin exposed, and feels his heart beat steadily beneath her.
"Monsters don't have hearts."
Loki hears footsteps a second before she does and vanishes, his gaze lingering on her for a split second longer. He knows it's Thor and he doesn't want to be there for whatever is going to happen. He can't be. Natasha catches up quickly and opens the door before the God can burst through it.
"Thor?"
Thor stops in his tracks and frowns when he realizes she's alone. Loki has warned her of this, despite his reassurances. The magical energy in her rooms must have spiked considerably for Thor to show up.
"Lady Natasha. I must apologize. I thought I felt Loki's magic here."
"His magic?"
She doesn't let him in. He'll get too close to find acceptable excuses to cover for herself. And Loki.
"Yes. I have grown up with it, although I must admit I have never been very good at identifying it. He has become very good at hiding it from everyone. I thought I'd felt it, stronger than in a long time. Are you certain he hasn't been near you? Perhaps he-"
"Thor. Hey, big guy. Relax. Loki hasn't been anywhere close to me. You'd know about it. I don't know what you felt exactly but I'm sure I'd be dead already if Loki was around. Unseen."
Her lies merge with her truths so convincingly and easily that Thor believes her right away. Unlike Steve, he still thinks her above lying. Thor is always honest, she knows the least he can expect from his friends is to do the same in return. But if she jeopardizes Loki now, she does it to herself. She can feel bad later but their connection needs to remain a secret. She still wants to learn, still wants to-
Natasha stops that train of thought before it goes too far and smiles up at Thor instead.
"I appreciate the concern but I'm fine."
"I apologize for the intrusion then."
She waves it off and they stand in awkward silence before Thor excuses himself and she shuts the door behind him again. She remembers Loki telling her that it's not very likely that Thor can pick up her unique magical signature but that he could still sense magic if there is a high enough concentration of it in one place. She guesses that has easily happened earlier.