Natasha observed everyone and everything at all times, a habit she could not break. Her head was on a swivel, looking out for any abnormalities, even while she was at home. So when Yelena stole her vest back, wearing it every chance she got and refused to wear a short-sleeved shirt under it, every alarm in Natasha's head set off. What changed?

xxx

Yelena was quieter these days. Her usual quips and teasing happened less often, concerning Natasha, of course, but the other Avengers as well.

Tony would greet her in his usual way and only get a small smile and a wave in his general direction.

Peter would try to talk to her about his latest class project, but he could tell her head wasn't in it.

Clint would offer to train with her, given their shared experience, but Yelena declined, despite her competitive nature.

Yelena would sometimes even refuse Natasha's hugs.

Now that, everyone noticed.

Despite the pair trying to keep a low profile, it was obvious to the team that Yelena's traumatic experiences have left her heavily relying on Natasha for a sense of security. Of course, no one looked down on her for it. After all, most of the heroes could relate in one way or another.

Clint has been mind-controlled and was an assassin, just like Yelena.

Sam, Steve, Tony, and Rhodey all had some form of PTSD.

Wanda lost her family and now has to live every day without them, missing what once was.

The Avengers understood her, so seeing her shy away from one of the only things that made her feel safe didn't settle well with them. And they didn't know her as Natasha did.

xxx

It all came to a culmination when Peter privately met with Natasha after he had hung out with the Russian.

"Ms. Romanoff, um..." Peter's eyes reached Natasha's, and Natasha immediately knew something was very wrong. "H-have you noticed Yelena's wrists?"

Natasha raised her eyebrows. She hadn't. How did she miss this? "What did you see?"

"Well, she pretended nothing happened but-" Peter scratched the back of his neck uncomfortably, shifting on his feet in thought. "She has this weird red ring around her left wrist. I tried to ask her what it was, but she shut me down and was quick to end the conversation. Do you know what it could be? I'm worried..."

An unsettled feeling washed over the woman. She knew exactly what that meant. Natasha rubbed her forehead for a moment, attempting to stay calm for the boy's sake. "I have an idea, yes... Thanks for telling me, kid."

Peter nodded and smiled slightly. "Of course. Let me know if that's anything I can do?"

Natasha's lip curled up, and she ruffled his hair before she set off in search for her sister, calling out over her shoulder, "I will. Thanks again."

xxx

Natasha eventually found Yelena wandering the halls of the compound. As expected, she was wearing her vest with a thin hoodie underneath, with earbuds in as if to block out the world. Natasha cut Yelena off, making Yelena huff and remove the earbuds from her ears.

"What do you want? Did Peter send for you?" she asked, knowing exactly why she was here and was already mentally cursing herself for letting Spider-Boy see.

"What if he did?" Natasha countered, crossing her arms.

"Then..." Yelena cleared her throat and averted her eyes. She didn't need to be Natasha's little sister to know how intimidating she could be, even unintentionally. "He didn't know what he saw... It's nothing, don't worry about it; you wouldn't care anyway."

"Hey, wait." Natasha softened and dropped her arms to her side. She hadn't expected Yelena to give in under her gaze so quickly. Maybe this had been going on even longer than she thought. "I do care, Yelena. Everyone does. This isn't the first time someone has mentioned how off you've been. You can talk to me. Whatever it is, you don't have to go through it alone."

"I don't..." Yelena's fingers flexed, curling in as if to conceal herself even more. Her mouth pressed into a straight line as she debated how she was going to get out of this one. "I'm fine. Things have just been a little weird lately; that's all. Tell the cool kids not to worry." Yelena stood a little taller and forced a toothy grin. "The world's best child assassin has got this handled."

"Hm." Natasha wasn't buying it. But pushing her would get her nowhere either. They were at a stalemate. "If something was going on, you would tell me, right?"

"Of course," the Russian answered quickly, tucking her hands into her vest pockets. Rookie mistake.

She could only get a quick glance, not wanting Yelena to notice, but there was a red line across her wrist, just like Peter had described. Natasha had to force herself to keep a straight face. "Okay then."

Yelena nodded once and pursed her lips, an awkward silence falling over the sisters. It was way too quiet in this hallway.

"Well." Natasha smiled a little and held her hands up. "I won't grill you anymore. I'll let you go." She wouldn't let this go. But she would allow Yelena the time to come forward herself.

"'kay. Thank you." Yelena began to put her earbuds back in, but Natasha stopped her before both could block her out.

"Wait. Can I have a hug first? You know, for the road. I've got a boring board meeting soon, and I could use the moral support." This was, of course, a lie. But making Yelena think it was for Natasha's sake might make her give in and accept the attention.

Yelena squinted at her for a moment, then rolled her eyes and wrapped her arms around her big sister. "You're a big baby."

Natasha laughed softly and rested her chin on her shoulder. "Yeah, right, you fell asleep in the last meeting you attended." She felt Yelena huff but was pleasantly surprised when a light kiss was pressed to her cheek before her sister let her go.

"Show the big boys who's boss, sis. Especially Rogers, that guy needs to broaden his horizons," Yelena teased, a little bit of her spark coming back.

Natasha fondly shook her head. Yelena would be okay. She knew she was strong. But she wished she didn't have to be so strong all the time.

xxx

A few nights after Peter came forward, something unexpected happened.

Natasha was sound asleep in her bed when her door creaked open, quickly snapping her awake.

"I'm sorry," came a soft, shaky voice. Natasha almost didn't recognize it.

"Yelena?" Natasha sat up on her elbows as her eyes adjusted to the darkness. There was her little sister, standing in the doorframe in her hoodie and vest, as usual, but there was something off about her. She seemed younger.

"Um..." Yelena closed her eyes for a moment, preparing for what she was about to ask. "Can... Can I stay with you?"

Natasha hesitated. It's not that she didn't want Yelena with her, but Yelena flat out asking for something like this was just about as rare as it came. She wasn't sure how to handle it yet.

"If you don't want me to, I can-"

"No, you can stay. Please."

"Okay..." Yelena padded over to the empty side of the bed and shimmied under the blanket, facing her sister. "Why is it you only have one blanket, you psychopath," Yelena made light, immediately trying to break the tension.

"In my defense, I wasn't expecting company," Natasha quietly pointed out, smiling to prove she meant no ill will.

Yelena only hummed in response.

The Avenger swallowed hard. If Yelena was here, it meant she was trying to do better. She had to show Yelena that she could always come here when she needed her. "Well, if you're cold-" Natasha opened her arms expectantly. 'Please. I know you need this.'

The Blonde instantly gave in, cuddling close to her favorite person. "Mm, you're warm..."

"Thanks, I tried." Natasha slid her arms around Yelena's waist, holding her, finally. This was already going better than the other day.

Yelena tucked her head against Natasha's shoulder. She was feeling very choked up and didn't want Natasha to see her cry. Not now. Just asking her to stay was enough vulnerability for today.

Natasha raised a hand to cup the back of Yelena's neck, gently stroking her fine baby hairs. "Are you okay?" she asked, her lips brushing the side of her head.

Yelena sucked in a quick breath, pressing harder against her sister. She should've known her facade wouldn't last long. "No...," Yelena admitted, her voice cracking with that one word. "I'm not, Nat..."

"What do you need me to do?" her sister asked, ready to provide her with whatever she wanted. Anything.

"Just stay... I need you to stay...," Yelena admitted, her fingers grasping to Natasha's shirt as she struggled for control. Her head spun as she continued to try not to cry. She felt weak for not being able to control her emotions.

"Hey, calm down, it's alright," Natasha reassured, stroking Yelena's hair. "You're okay. I've got you."

"I-I need..."

Natasha knew what she was going to say. And she wasn't going to let her finish. "You don't. Just hold onto me, okay? I'm here to make it easier."

Yelena whimpered, and the waterworks finally released, quickly soaking Natasha's shoulder. "Nat... Nat... I'm sorry..."

The Avenger hushed her, carefully kissing the side of her head a few times. "Focus on me. Don't apologize. Get through this first before you wallow in it, or else there's no use. I've got you." Yelena's nails dug into her back, making Natasha have to bite her tongue to hold back a yelp. But this was still better than the alternative. "Yelena. I love you. I'm going to protect you, I swear on my life."

"I..." Yelena squeezed her eyes shut and buried her nose into Natasha's neck. She couldn't speak. She wanted to tell Natasha how much she meant to her, but no words would come out.

"It's okay." Natasha slipped her hand under Yelena's vest and stroked her thumb over the fabric of her hoodie. "Just breath."

They laid there together for a long time, Yelena's grip on her sister never wavering. Natasha would chase away the bad thoughts she kept telling herself. She would have to believe that because the guilt was beginning to consume her.

"Do you want to talk now?" Natasha asked against her shoulder after a few more minutes of silence, her quiet words caressing Yelena's ears and making her feel calm despite the loaded question.

"You already know... don't you?"

Natasha hummed sadly and nodded. Those red marks. They were from handcuffs. Yelena was using them to help her sleep, and they were hurting her. It was why she was here now.

"I'm sorry... Sometimes it's just... easier. I need control, and they made me feel... I don't even know anymore..."

The redhead breathed out before she eased out of Yelena's arms, choosing instead to hold the side of Yelena's face in her hand. "You want to feel secure. You feel more in control of yourself when you're locked up. Right?"

Yelena merely nuzzled against Natasha's hand.

Natasha smiled softly and stroked her cheek a little. "I understand, Yelena, I really do. It... took me a while to get used to sleeping without it. But it's hurting you." The Avenger dropped her hand from Yelena's face and carefully slid her fingers down to her wrist, barely grazing her sleeve as if to ask for permission to look at it.

Yelena's nodded slightly. She already knew anyway. There was nothing to hide.

Natasha carefully rolled up the Russian's hoodie, revealing the agitated red ring she was dreading to see in its entirety.

Yelena tilted her head and followed Natasha's gaze, cringing at her exposed skin. She had gone too far. Natasha was right.

"Hey. Look at me."

The assassin's eyes raised, scanning her irises for any sign of disappointment.

Natasha sighed, then created a ring with her thumb and pointer finger around Yelena's wrist, holding it tight.

Yelena's mouth parted, and her eyes widened.

"Is that better?"

Yelena swallowed hard, her gulp audible. "Maybe..."

Natasha pressed her forehead against Yelena's firmly, making sure she had captured Yelena's full attention. "If you ever feel like you need to cuff yourself again, come to me first. I. Will. Help. You. Alright?"

A tear ran down the Russian's face as she silently agreed. Natasha wanted to help her. She believed her.

"Okay." Natasha lifted Yelena's hand to her face and softly kissed the abrasion, lingering for a moment. She wanted to put every ounce of love she had inside of her into that mark, one that would never return under her care.

Yelena closed her eyes and all but fell against Natasha's shoulder when she pulled away, exhaustion finally taking her in its grasp. "Thank you; for stopping me..."