"Tony couldn't have come upstairs to us?" Yelena grumbled, holding tight to the inside of Natasha's elbow as she led her down the short flight of stairs to the lab. "And why doesn't he have an elevator to get down here?!"

"Well, he usually just flies in through the ceiling," Natasha replied with a short laugh to break the tension, bringing her sister closer when they reached the last step. "But if you care so much, maybe you can ask him to install one. He'd do it for "mini Romanoff.""

Yelena would've shoved her if it weren't for Natasha being her stand-in for a walking cane. "Shut up..."

"Ah, there you are. Romanoff, mini Romanoff."

An elbow dug into Yelena's ribs.

"Sorry making you use the stairs." Tony thoughtfully began stroking his goatee. "Huh. Maybe I should have put more thought into that..."

The elbow dug deeper and Yelena was quick to fight back with a defiant huff.

"Anyways." The inventor threw his hands out to the side in what could only be a Tony Stark pose. Some think it makes him feel taller. "I have good news and bad news. How do you want to take it?"

"Good news."

"Bad news."

Natasha and Yelena answered respectively. Natasha instinctually shot her sister a look but was quick to drop it.

Yelena just kept staring straight ahead, her shoulder occasionally bumping against her sister's. Bad news first. Always. There was no use in standing there, letting someone butter you up to cushion the blow. Cut first, bandage later. Sometimes don't bandage at all. Life was hard. Deal with it.

But Natasha didn't want to live like that anymore, not when she had someone to live for. She needed a win. Yelena was miserable, and the fact that there was less than pleasant news made Natasha's stomach perform backflips. With Yelena, she had hope. She wanted to believe in something good.

"Okay, so..." Tony leaned back and crossed his arms, eyeing the sisters as he tried to get a read on them. Dang assassins. "Dealers choice?"

Natasha gave a short nod. "Out with it, Stark. Is she going to be okay?"

"Of course she will; she's with us. But when it comes to her eyesight, that's a whole different story."

Yelena moved closer to her sister but held back from taking Nat's hand. She trusted Tony. When she could see him. But everything was different now. Yelena knew Natasha was really there, and she obviously wanted to believe that she wouldn't lead her into something dangerous. That didn't mean that the feelings would just go away. She needed to keep her guard up. "Was that the bad news?"

"I wish that was the worst thing I had for you, kid."

Something about that sentence deeply disturbed the redhead, and she was quick to place herself in front of the Russian. "Tell us," Nat almost begged, looking Tony in the eyes as she silently pleaded for him to tell them everything. No corners cut.

Anything they could do to keep her world safe.

"Well, then I guess it's time for the good news." Tony nodded to Natasha, the only one who could see him and his conveyed sympathy. "I took the device apart. As the old man probably told you, they are very advanced. Much more advanced than we thought. But not too complex for me. I think I know how what I have to do to reverse this, but..."

Yelena perked up. Tony sounded weird, almost like he was unsure of himself. This was new. Was this really the Stark she knew?

Tony wiped his mouth and looked up, the once fresh cut from Yelena now scabbed over and shining in the light. "The device uses a liquid that turns to gas when it ignites, blinding anyone within its radius. I found the trigger, and not all of the liquid had been expelled. But it's too risky to extract it without blinding myself in the process."

"What are you trying to say?" Natasha urged, not liking the direction this conversation was heading. "Because if you're going where I think you're going, there is absolutely no chance that I-"

"I'll do it."

Tony and Natasha jerked their attention to the young assassin.

"I did some bomb defusal while I was in the Red Room." Yelena shrugged nonchalantly, unaware of the pain behind her sister's gaze. "As long as you can guide me from a safe distance, we should be okay."

"And if you fail?" Natasha whispered, her voice shaking just enough that Tony caught onto it.

Yelena touched the back of Natasha's shoulder with just her fingertips, causing Natasha to turn to her and watch her intently with every fiber of her being. It was just them now. Yelena smiled softly, her thumb now rubbing the top of her sister's shoulder more for Nat's sake than her own. "Then what more could I lose?"

"We've only got one shot at this." Tony uncomfortably shifted on his feet, his gaze far away in thought as he reconsidered his options. "I won't make you do this, kid. Only do this if you're up for it. There might be another way."

"It's safer for all of you if I do this."

"Are you nuts?!" Natasha grabbed Yelena by the shoulders, effectively startling her into making near-perfect eye contact. "This is crazy, even for you! Let me do it. I have the same skill set as you, and I'm not currently blind!"

"And I would like to keep it that way." Yelena pushed Natasha's hands off her, informing her she was serious and did not want to be coddled. She was blind, yes. But that didn't make her any less beneficial. Besides, it wasn't a win-lose situation. If Yelena extracted it, Tony could synthesis a cure. If she didn't, and accidentally set off the device, she couldn't get more blind. Nobody else would have to suffer.

Natasha scoffed and shook her head, unable to believe that Yelena was really considering doing this. Not only considering, but actually following through with it. "No. You can't. Tony, you're a man of toys. Are you telling me you don't have a machine that could take this thing out without putting my little sister in danger?"

Tony rubbed his forehead and sighed. "Not one that is efficient enough. I'd have to create a whole new one for this task, but that could take too long."

"Then try harder!" Natasha yelled, facing the genius with such fierceness that even he took a step back. "We can not put each other at risk here, and especially not a soldier that is already injured! Find a way. A different way. End of discussion."

"That is not your decision to make," Yelena sternly reminded, ready to fight Natasha for the right to make her own decisions. To her, there was only one option.

"You can't just-"

"Stark."

Tony lifted his head in Yelena's direction, expecting fully to be yelled at or told to make Natasha stand down. That is, after all, what he felt he deserved. He made incorrect calculations. It wasn't supposed to go this way. Yelena wasn't supposed to get hurt.

"Can you give us a minute?" Yelena asked much softer than either Avenger expected.

Even Natasha backed off for the time being, eyeing the assassin curiously.

"Alright." Tony gently clapped his hands together before he began walking towards the staircase. "I have something I need to grab anyway." He paused halfway up to turn back to the blonde. "You good, mini Romanoff?"

"I've got this. Just go get ready," Yelena answered, standing her ground in front of her sibling.

"I trust you know what you're doing, kid."

Yelena swallowed the lump forming in her throat as she listened to the man ascend the rest of the steps and close the glass door behind him. Telling him she trusted him too was on the tip of her tongue, but she couldn't get it out in time.

This was her home now. Everyone here treated her so well that she didn't even know what to do with it. But Tony trusted her. She had to make that worth it.

"Nat. Help me find you."

Natasha gulped before she gently took Yelena by the arm and guided her until they were face-to-face.

Yelena gripped her sister's wrist for a moment before she ran her fingers up Natasha's arm until she reached the side of her neck. She looked up slightly and offered a small smile. "C'mere."

Natasha huffed softly but still gave in and brought their foreheads together. "You can't just be cute and get out of this one, Belova."

"I'm going to do this with or without your permission." The Russian eased her hand back to run her fingers down the nape of Natasha's neck. "But I would prefer it if you were there with me. I need you. And so does the team. You can't convince me there is another way."

"Dang it, rooskaya..." The Avenger shook her head before she pressed against her harder. "You-"

"Do you trust me?"

"With everything I have," Natasha answered instantly and honestly.

"Then prove it." Yelena let her go and took a hesitant step back. "I know I can do this. But I need to know if you have faith in me too."

Natasha chewed on her lower lip in thought. Of course she had faith in her little sister. But it wasn't that simple.

"Natasha." Yelena crossed her arms and tilted her head. "Please?"

"You aren't being very fair," her sister finally answered, Yelena knowing that Natasha smiled after she finished her sentence. "I'm supposed to protect you from things like this."

"Things like what, devices that blind me? Been there, done that." Yelena laughed, but it was a lot lighter than Natasha would have expected. "You are not entitled to protect me, poser." She reached for her sister's hand, who met her in the middle and gave her fingers a light squeeze. "It was my mistake. I didn't see the grenade. Now there is a chance for a cure, and I have to take it. I'm the most ideal person to do it. I will not fail."

"Okay."

"Okay?" Yelena echoed as she raised a cautious eyebrow. "Just like that?"

Natasha smiled softly and lifted Yelena's hand to her mouth to kiss the back of it. "Just like that. You've grown up a lot, Yelena."

"Bez shutok," Yelena replied with a pleased grin. "I'm even taller than you now, see?" She stood up on her toes just to irritate her big sister, that big smile still plastered on her face.

"I know, you love reminding me," the redhead grumbled before she took Yelena by the shoulders to steady her. "I love you, mladshaya sestra."

"I know you do," the assassin whispered as she pressed her nose against Natasha's wrist. "I'm going to do this. And I'm going to do it right."

"Alright, ladies, have we come to a mutual agreement?" Tony interrupted as he jogged down the stairs, an unfamiliar small box in his hand.

Natasha searched Yelena's face one last time for any uncertainty, but all she found was a solemn and determined young woman who had so much love behind her unseeing eyes. She couldn't help but smile. "She'll do it," the Avenger confirmed, her gaze never leaving Yelena. She was still afraid, but it was about time she put money where her mouth was. Yelena could do this.

Tony grinned. "Great, because I've got a friend here that could make this a whole lot easier." He opened the box, which Natasha now realized was simply a glasses case.

"Assassins-" Tony held up an appropriately dorky pair of glasses, much like the ones he'd commonly wear on his days off. "Meet E.D.I.T.H."

xxx

"And this is supposed to help us, how?" Yelena questioned as Natasha helped slip the frames onto her face.

"There is a camera built into the lens," Tony began explaining, firing up one of his many monitors. "Using E.D.I.T.H, I can guide you through the screen from a safe distance."

Yelena pushed the glasses up on her nose and scoffed. "If this is so high-tech, why did you design them to look so stupid?"

Tony fake gasped and held his hand to his chest, then remembered why they were doing this in the first place. "Wait a minute..."

"What?" Yelena shrugged. "I don't need to see that it looks stupid when I know who invented it."

Natasha clamped her mouth shut to hold back her laughter when Stark gasped for real this time.

"Wow, Belova, I am hurt. Seriously. But good thing that's just a prototype for a present that is not going to you."

"Wait, wait, wait, let me guess." Yelena held her finger up in the air and pretended to think about it. "It's for Spider-Boy. Hold your applause, please."

"Yes, and don't tell him about it," Tony warned, his tone serious enough to make Yelena stop smiling.

"Why?"

"Because." Tony sighed heavily and shook his head. Natasha noticed his gaze sadden for just a moment. "It's not time yet. Something has to happen first."

"What, does he have to hit puberty first?" Yelena joked, and Natasha promptly whacked her shoulder with the back of her hand. Yelena jerked away with a small 'Ow' but kept her mouth shut after that. She knew better.

"Okay, can we focus here?" Natasha looked between other people in the room and tapped her watch loud enough for Yelena to hear. "We don't know the half-life of this stuff. The sooner we can remove it, the better."

"You're right." Tony pushed his wheeled chair away from the desk and rolled over to another monitor across from him. "And we are... online!" He spun around to face Yelena, a satisfied smile plastered on his face. "Alright, kid, go ahead and wave your hand in front of your face to make sure it's working properly."

Yelena groaned dramatically before she slowly waved her hand around as she was instructed.

"Great!" Tony snapped his fingers in triumph. "Everything is working beautifully!"

"Would you like a pat on the back?" Yelena whispered under her breath, a playful smile tugging at her lips. Stark made it far too easy for her.

Tony ignored her and began grabbing several implements off of his disorganized desk. "Alright, children, gather around and sit on the floor. Natasha, with me."

With a quirked eyebrow, Yelena slowly lowered herself to the floor, sitting criss-cross in front of her big sister and Iron Man himself. This position made her nervous. Her hands were free, but she felt moments away from being cuffed and dragged away to be beaten and interrogated.

She wanted to fix this more than anything.

"It's okay," Natasha gently reassured, nodding to Tony to silently relay what was happening.

Tony got the message and moved further back on the floor, distancing himself from the blonde. "It's just us, kid. I promise. If you want, I can even get F.R.I.D.A.Y. to scan the building."

"No. No, I..." Yelena lightly slapped the sides of her face and exhaled loudly. "I'm fine. I'm fine. Tell me what to do. I'm ready."

Tony looked to Natasha, who gave him another nod. Trusting her judgment and appropriately too afraid to question anything, he leaned forward and neatly placed several small tools in front of the Russian. "Alright. Here's what we have to do..."

For the next half hour, Natasha watched as her long-time friend instructed her little sister on what to do with the device.

Yelena ran her fingers across every tool with meticulous and precise action, committing every scratch and imperfection to memory. For once, the grueling training she went through was useful for something other than death and destruction.

Natasha occasionally helped by handing Yelena objects because her sister trusted her touch more than Tony's in her state, but most of the time, she found herself staring in awe. The woman in front of her looked so much older, more mature. Everything she did had intent behind it. Every move she made was well planned. Yelena could do this.

The redhead hummed quietly and smiled. She was impressed. Yelena had really grown up.

"And that should do it," Tony proclaimed, leaning back and placing his hands on the floor behind him. "Anything you want to go over again?"

"No." Yelena picked up one of the small tools again and repeatedly flipped it over in her hand. "I know what I have to do. I can do it."

"Are you sure y-" Natasha began but was quickly cut off.

"I'm sure." Yelena looked towards Natasha and gave her a confident nod, Natasha's heart warming with affection for the woman. "So let's get ready."

xxx

The setup was simple enough. Natasha and Tony sat at the computer monitor to watch the process through E.D.I.T.H just out of the radius of the gas in case something went wrong. They each wore a pair of safety goggles for that same reason. Yelena was seated at a table behind a protective shield, her tools laid out in an orderly fashion next to the disassembled grenade. E.D.I.T.H. rested on her nose.

Tony booted up the screen and an intercom he and Nat could share and relay the instructions more clearly. It was now or never. The inventor leaned forward and tapped into the comm: "Are you ready to rock and roll?"

"Ready when you are, chief," Yelena answered, running through the steps in her head for the millionth time. She knew Stark was to guide her through the process, but she had been trained to complete tasks solo. It was a hard habit to break. Yelena had to be perfect.

"Alright. Pick up the clamp on your far right."

Natasha slumped back in her chair and tried not to chew all of her fingernails off as she feverishly watched the monitor.

Tony continued giving her sister slow and clear instructions, Yelena switching tools as needed as she carefully disassembled the device that caused her toil. But that was just the easy part.

Click

"Freeze, Yelena," Tony barked, and Yelena immediately stopped moving.

"Talk to me, Stark," Yelena ordered through clenched teeth, having also heard the sound of certain doom. "What do I need to do?"

Natasha scanned the screen and found that Yelena had brushed against the spring lock, moving the grenade one step closer to expelling the rest of the gas. She needed to remove the vial. Now. "Rooskaya. You need to slowly move the pick in your left hand upward. Slowly. You got it?"

Yelena licked her lips and nodded once. "Towards me or in front of me?"

"In front," Tony confirmed, Natasha making sure to move away to let the man finish the job. "If you lift the pick too high now, the spring will release, and so will the gas. You need to hold it in place before you can extract it. Understand?"

"Affirmative." The assassin carefully adjusted her grip on the tool and ever so slightly tilted it upward.

Click

Yelena held her breath, but no further noises followed. "Tell me what you see, guys. Do I continue with the plan?"

Tony ran his hands down his face and looked towards Natasha, who met his gaze with a grim expression.

"Guys? I can't hold this forever."

"Okay." Tony took a deep inhale before he leaned further into the intercom. "I'm not trying to scare you, kid, but if that spring moves any more, you're about to get a face full of disappointment. You can not let the grenade know that you're messing with it. Yelena, you are so close." Tony gestured for Natasha to take over, knowing that listening to her big sister was exactly the push she needed to complete the mission.

Natasha swallowed hard before she dragged the comm closer to her side of the desk. "Steady hands, sestra." The redhead glanced back up to the screen to make sure there wasn't something obvious they were missing that would make this easier. "Trust your instincts," she finally told her, regaining her control of the situation with a small smile. "Sometimes you tell me you've done something so many times you could do it with your eyes closed. It's time to prove it. Do what feels right. You can only get so far with us holding you back."

Yelena needlessly adjusted her grip as fear crawled up the back of her neck. "Is this a test?" she whispered so softly E.D.I.T.H. could barely even pick up.

"It's not," Natasha quickly reassured, a newfound sense of urgency in her voice. "But it really is left in your hands now. You're resisting pressure that we cannot feel. We didn't prepare you for this, and we're sorry."

Tony looked up and was surprised to see a silent tear roll down Natasha's cheek.

"But I trust you." Natasha cleared her throat and nodded once. "You can do this."

Yelena was silent for a moment. She could feel sweat starting to form on her forehead, and her hands ached from staying in the same position for too long. The darkness that had become her normal for the last few hours was closing in on her, and Yelena found herself squeezing her eyes shut to try and block out any interference.

"You can do this."

The Russian slowly opened her eyes as the gentle voice of her sibling filled her ears again. She knew what she had to do. And they were not going to like it. "E.D.I.T.H. Power down."

The Avengers' eyes widened as a bunch of error messages appeared on the monitor before everything shut itself down. Natasha grabbed the intercom, but there was nothing but static. "What is she doing?" Natasha whispered under her breath, her heart making itself known with a thunderous roar. She wanted to run to where she knew her sister was. Yelena wasn't far. She could reach her before anything bad happened.

"You said you trusted her." Tony offered Natasha a quick shoulder squeeze. "So make use of your word."

Natasha returned the gesture with a stiff nod.

The silence in the lab that followed weighed heavily on Natasha's chest. No buzzing, no clicking, no tapping. Nothing. In any other world, this would be a good sign. But to the Avenger, used to Yelena's boisterous and mischievous energy, a quiet environment was practically unheard of. Natasha shared an uneasy glance with the man next to her, but he only smiled and flashed a thumbs up. Tony had faith and was showing it. It was about time Natasha showed it too.

"Hey, guys?"

Natasha jumped out of her seat, effectively startling Tony, who had just put his feet up on the table. The comm had been reactivated and so had the screen. E.D.I.T.H. was pointed towards Yelena's lap, and in her hand, a small tube.

"This is it, right?"

Natasha laughed and ran her fingers through her hair, serotonin, dopamine, and all of the other good chemicals hitting her all at once. "You did it! I..." She shook her head and dashed around the desk and towards the area they had set up for her little sister. When she saw Yelena she was standing, gingerly holding the tube in one hand as she took E.D.I.T.H. off with the other. "Yelena!"

Yelena jerked towards the voice and grinned widely. "Nat! I did it! I, I was useful!"

Natasha dodged the barrier and took the vial from Yelena's hand, inspecting it for just a moment before she placed it on the table and tugged Yelena into her arms.

Yelena chuckled and buried her face into her shoulder, the grin returning to her face when Natasha kissed her temple.

"I'm so proud of you. So proud," her sister softly commended, Yelena only sinking further into her embrace.

Suddenly she was absolutely exhausted.

Tony finally caught up to them, a shining smile also present on his face. "Good work, kid!" He refrained from touching her but made sure Yelena knew that he was proud too with kind words and praise.

Yelena wasn't used to it, but it felt nice to have a positive relationship with a man.

Tony picked up the vial from the table and held it up to the light. "You should take her home, Nat," he eventually suggested, looking at the two women who have yet to let go of each other. "Home home. I can synthesize a cure from this, but it will take some time. I've got it from here."

xxx

So this story is becoming more than I expected lol. There will be at least one more chapter, but I won't be surprised if it turns into two. But this is a fun project, so I hope those of you reading are enjoying :)

xxx

bez shutok - no kidding