Part 1

Bruce stepped outside and took a deep breath, forcing the majority of his anger out of the way. He laced his fingers behind his head and groaned, closing his eyes. The cause of his aggravation was the Avengers. He was one of six, and the other five were inside the tower bickering like children. Stark and Thor were fighting over who was strongest, as well as whose girlfriend was the best, Rogers was trying to break them up, and Natasha and Barton were at the firing range, training. He breathed out, listening to the sounds of the city. He always hated being in large, populated areas; he was afraid of who could get hurt because of him.

He was beside the street, and though it was Manhattan, it was very quiet. The street by which he stood was deserted except for him, and the only light was that of the streetlamps which washed the street with an eerie orange glow.

The sound of something being slammed against a dumpster made him stiffen, and he turned his head to get a better reading on where the sound had come from. He could hear the distant sounds of sirens and horns from the main section of New York City a few miles away, but for the moment there was silence.

After a moment he heard the sound of scuffling from an alleyway nearby and crept closer. A heavy thud echoed through the street, followed by the sound of footsteps retreating from the alley.

He stood, back against the brick wall of a building, ran around the corner of the apartment building, and tripped over something on the ground, face-planting on the pavement. He swore under his breath as he surveyed his scraped up arms, wiping them on his shirt to clean the blood off them as best he could.

Moving into a crouch, he turned to face whatever had tripped him. He felt his breath leave him as he stared in astonishment at the small figure curled up on the ground in front of him. It was a girl. A child, by the look of it.

He crawled over to the girl and gently rolled her onto her back, revealing her to be a young woman who looked to be in her mid-to-late-teens. The reason he had thought he a child was because she was skeletally thin. She had dark, curly hair which fanned out around her head, dry except for a wet patch near her hairline. Bruce gently touched his hand to the spot and clenched his teeth when he saw her blood stain his hand. He touched her ribs, testing to make sure none were broken and was relieved to find that none appeared to be. He leaned over her and held his breath, listening for her breathing.

He let out a sigh of relief when the sound of her breathing reached his ears, but concern washed over him again when he realized how shallow it was. Her face was pale, almost grey, and her black jeans were torn and bloody; there was a deep gash in her calf. Through it was the middle of summer, she wore a back trench coat, which had come undone in the scuffle, revealing a black top, also torn. Bruce frowned at a particularly long tear and touched it, grimacing when he felt blood drenching her top.

He looked around, wondering who had attacked the girl, but couldn't find any clues from his position on the ground. Making a split-second decision, he propped her up and wrapped his arms around her. Standing slowly, he adjusted her body so that he could carry her easily, and felt another rush of concern at how light she was. He began walking quickly towards the entrance to the tower and entered without incident, looking around nervously the entire time.

He quickly made his way to the floor his lab was on and entered his room, locking the door securely before setting her on the cot in the corner. He made his way to his phone and hesitated, looking over at the girl before picking his phone up and dialing a number on it, his hands shaking with suppressed anger. Anger at the others, at S.H.I.E.L.D., at whoever had attacked this girl, and life in general. He closed his eyes and waited impatiently for the one person who could calm him down to pick up the phone. After an eternity, their voice reached his ears.

"Bruce? Is everything okay?"

He cleared his throat. "Natasha? I need your help."

"Bruce? What's wrong?" Natasha's voice echoed through the phone.

"I can't say," Bruce answered, knowing full well that Tony could hear everything said if he wanted to. "I need you to meet me at my lab immediately."

"Why me?" She answered, "Wouldn't Clint be better for a project?"

"No," he answered, "Just you. You must come now. Please."

Silence answered him.

"I'm on my way," she finally said. Bruce sighed in relief as the line went dead. Dropping his head into his hands, he reflected over all the girl's wounds, wondering what all he would have to fix.

He went to the bathroom and grabbed a rag, holding it under the faucet until it was drenched in warm water. He glanced up at the mirror and gazed at his reflection for a moment before heading back to the bedroom. The poor girl was still out cold, so he stood beside the bed and began cleaning the blood from her forehead gently. When the rag became saturated with blood, he headed to the bathroom and grabbed a second rag before heading to her.

He turned as a knock sounded from the door but before he could answer it, a groan came from the bed behind him. Bruce turned around, shocked. "No, no, no, you can't be awake," he muttered, going around the bed to where she lay, forgetting about the person at the door.

Her eyes fluttered open, revealing them to be bluish grey with a ring of dark blue around the iris, nearly identical to Rogers's. "Where am I?"

He looked around for help, but turned back to her. Her pupils were dilated to the point that her irises were barely visible, and her skin was pale and clammy. "Answer me," she said, putting as much venom as possible into her tone, though pain was clear in her voice.

"Easy," he said gently, sitting down on the bed next to her and pressing the warm rag to the blood-soaked patch of hair near her forehead, "You're safe."

"Where am I?" she repeated, her teeth clenched against the pain.

"You're in the Stark Tower," he answered, removing his glasses and pinching the bridge of his nose.

"How did I get here?" she asked, her voice terrified.

"I found you unconscious in an alleyway outside the tower," Bruce replied, "You're injured; I don't know how badly."

She opened her mouth, but before she could say anything else, another voice came from behind Bruce. "Who's this?"

Bruce stood and turned to face the red-haired woman behind him, who stood motionless in the doorway. "Natasha, I need your help."

"What is going on?" The girl demanded, struggling to sit up.

"I'd like to know that as well," Natasha said, raising her eyebrow.

"Tasha, she's hurt, that's all that matters right now," Bruce said, crossing his arms in exasperation.

"I'm fine," the girl said, sliding off the bed and onto her feet. "I don't need your help."

As the two adults watched, she doubled over, gripping her midsection and lifting her injured leg off the ground. She caught herself on the edge of the cot and sucked in a breath, glaring at the adults as they jumped forward to help her.

"I don't need help," she snarled, her irises all but overcome with black from the pain. Bruce understood what had just happened and he felt a surge of anxiety at the severity of the situation. He could see sweat beading on her forehead and could see the strain on her face from the effort of holding herself up.

"Please," he said, holding his hands out in supplication, "you're hurt. Let us help you—"

"Why should I trust you?" she asked, her voice trembling.

"Because we're all you've got," he answered.

She stayed silent, watching the two and weighing her options. She looked at the window and the darkness outside, and Natasha saw helplessness flash in her eyes, something she was familiar with. The girl nodded, and the adults noted her shaking hands. She was terrified. Bruce was reminded of an injured bird.

"Alright," Banner said, sighing in relief. "Natasha, can you help her back into the lab? We need to get her onto a flat surface."

Natasha nodded and stepped over to her before lifting her up and helping her towards the door. "On it."

Bruce nodded and opened the door for the two women before gathering up his supplies and clearing off one of the tables. As Natasha set the girl on it, she looked up at them, her eyes sparkling in pain. There was thanks there, but no trust.

Natasha watched the girl in amazement as Bruce wrapped the girl's leg, cleaning the blood and filth from her skin. Athough this girl had to be in serious agony, she barely showed it at all, except for a hiss of pain every now and then. Honestly… she reminded Natasha of herself a bit.

"Okay," Bruce said, stepping back from the girl to get a good look at her injuries. "Your leg should be alright; just don't go jumping off any buildings anytime soon." He said it in jest, but a sheepish look flashed across the girl's face. She nodded. "Natasha, this is where I need you," Bruce said, turning to her.

"Alright," she said, stepping up to the table.

"Okay—" He paused for a moment, frowning slightly. "What's your name?" Bruce asked suddenly.

The girl scowled, her stormy eyes narrowing a bit as her eyes narrowed in distrust.

"It's alright," he said, backtracking, "You don't have to tell us—"

"It's Katie," she said shortly, looking up at Natasha and locking eyes with her. Something about her gaze made the assassin shiver; something about her seemed so familiar, but she couldn't place a finger on what.

"Katie," Bruce said. She nodded. "Alright, I need you to push up your shirt to a bit above your ribcage so I can get a good look at the wounds you received. Can you do that?"

She nodded slowly and nervously glanced in the older woman's direction. She lifted her top up, but her trench coat made it difficult for Bruce to see.

"Do you mind taking off the coat?" Bruce asked. "It would make it easier to see if you did—"

"No," she said firmly.

"Why not?" Natasha asked. Katie turned to face her, eyes cold and calculating.

"It is not your concern," she said menacingly, tugging her top down, wincing as she did so.

The two girls glared at each other and finally, without breaking eye contact, the elder spoke to Banner. "Bruce? Leave, I need to speak to Katie alone."

Katie's face remained expressionless, although apprehension flashed in her eyes.

"Sure," he said resignedly, stepping towards the door. "Just try not to break anything."

As the door closed behind him, Natasha sat down backwards in a chair, facing Katie. The younger girl watched the older carefully, rather like a bird watching another animal, wondering whether to fight or to flee.

"You do realize that we're trying to help you?" Natasha asked, raising her eyebrows. The girl clenched her teeth, obviously not buying it. "Please, just do what Bruce says so you can get better."

She laughed humorlessly. "Why should I trust you?" she asked.

"We're the good guys," Natasha answered.

Katie's eyes burned with anger and she sat up, her fists clenched.

"You have no idea how many times I've been told that," she said, fury in her voice. "You don't know anything."

"The why don't you tell me?" Natasha asked, standing up. Natasha noticed that the girl was taller than her by several inches and that she looked ready for a fight, despite the fact that her pallor was now a chalky grey.

Katie laughed bitterly again, never taking her eyes off the Russian assassin. "I know you. You're an assassin. Your specialty is interrogation. I won't talk to you."

The woman looked carefully at this girl, who knew about her though they had never met. "And who will you talk to?" she asked.

"Banner," she answered.

Natasha shrugged. "Bruce!" she called. He stepped back in the room.

"Yes?" he asked, rubbing his hands together. Natasha stood up.

"You try talking to her," she said, exiting the room and heading for Stark's files. It was time to do some research on this mystery girl.

I relaxed a bit when Natasha left. I didn't feel comfortable with her around me. Bruce sat down in the chair Natasha had just vacated, and I watched as he took a pair of glasses and placed them on his face. He looked up at me, his dark brown eyes kind and warm.

"So Katie," he began, his voice calm, "Why don't you let me see how bad your wounds are? If you lose much more blood, it could be very bad for you. The amount you've already lost is unhealthy. I'm amazed you're not suffering any majorly ill effects from it."

My head tilted a bit, and I blinked as a reply formed itself in my head. "I've had worse," I said truthfully. Being captured by Nazis outweighs being slashed by a switchblade, although being stabbed isn't the best thing that could have happened.

"Be as that may," he replied, a faint smile on his lips, "We still should treat your injuries before they become too serious."

"Do I have to take off my coat?" I asked, feeling my muscles tense up. I was more than ready to fight my way out of here if need be, although I would prefer not to.

"Not unless it becomes the difference between your losing your life and keeping it," he answered, smiling wryly. "If it comes to the difference between life and death, would you remove it?"

I nodded and lifted my shirt again, hands shaking. He leaned forward and shone a flashlight on my side, instructing me to lie on my back, which I did. His hands were cold, and he gently probed the cut on stomach and the area around it. After a few minutes, he sat back, his face grim.

"What is it?" I asked nervously.

"You need surgery," he answered tersely, rubbing the bridge of his nose.

"What?" I asked disbelievingly, sitting up.

"You need surgery. Your cut is still bleeding, and it's deep," he replied blankly, retrieving his supplies and returning to my side. He pushed me back onto the table, leaving no room for argument. "If you don't receive medical attention, you will die."

I paled, and I nodded, my mouth dry. "Okay."

"Alright," he said, pulling out an anesthetic mask. "I need you to breathe this in."

"What?" I nearly shrieked.

"This is a kind of gas that will help you to fall asleep so you will not feel pain while I sew up the afflicted area," he explained.

"I know what Anesthesia is, and no."

"What? You—" he began anxiously.

"I said 'no'," I answered angrily, trying to sit up. "I'll take pain medication, but I'll be awake. I'm not going to be out cold in a stranger's house while he has access to anything that could cut me open."

He pressed his lips together, frowning. After a minute, he nodded, his eyes finding mine again. "Alright. Take these," he handed me a couple light blue pills, "And lie still."

He went to work stitching up my wound while I laid back on the table. I was very uncomfortable, but I stayed still. The medicine worked remarkably quickly, but I could still feel the pull and tug of the needle through my skin, and it made me sick.

"Dammit," he said some time later, the blood draining from his face. He had started to pack up, removing his bloodstained gloves, and gone to make sure the stitches were secure. When he had, his fingers had brushed up against another gash on my back, one that I had been hoping that would be small enough for him to ignore.

"What?" I asked, clenching my teeth. Despite the painkillers, I was still in a lot of pain, just not nearly as much as I would have been in.

He looked up at me and held up his hand, which was scarlet. I the blood drain from my face as the realization dawned on me that I was about to be discovered, and that there was nothing I could do about it. My heart rate picked up as I was faced with two choices: take off my jacket and exposed my true identity to this stranger, or bleed out in said stranger's laboratory.

"How bad is it?" I asked, forcing my voice to remain calm. I sat up and bit back a scream of pain. I tried to play it off, but Banner wasn't fooled.

"I can't tell how bad it is because of the jacket," he answered, pursing his lips together. "You said you would take it off."

I closed my eyes, drew my knees to my chest, and nodded, fear flooding through me. I fought back hysteria as flashes of memory surged through me, sending adrenoline pumping through my veins. "Take it off. But please…" I was begging, hysteria rising through me as I felt his hands on my shoulders, sliding the blood-soaked material off my arms and off my body. "Don't kill me," I whispered. I felt him freeze next to me as I wrapped my arms around my knees, burying my head in my arms. He's going to kill me—

"Who are you?" he whispered, wonder in his voice.