-Flashback-

The night before Grace woke up screaming. Wriggling about in her sheets she sat up suddenly, in a cold sweat. She had had the same dream again and it made her stomach churn. It had all be so real. She heard heavy footsteps outside and a shaft of light flooded into the room as Steve rushed over to her shaking body, wrapping his arms around her, like he had done every night that week. When she first came to them, she hadn't felt like this. But as time went on, the nightmares had become worse and more vivid. Steve hated seeing her like this, the girl that always seemed so happy in the day, turned terrorised and vulnerable at night. She didn't deserve this, but part of him liked to be the one to comfort her. She quietly cried into his chest and he kissed the top of her head. Sniffing, Grace looked up at him so their faces were inches apart. Steve looked deep into her beautiful glassy eyes, the eyes which everyday he found himself lost in. Instinctively, he moved his head forward, softly placing his lips on hers. His first kiss since Peggy and he couldn't imagine it happening with anybody else. It felt so right. The girl was startled by this but slowly began to kiss back, closing her eyes. Suddenly she pulled away bringing her fingers to her lips and Steve quickly jumped from the bed, looking embarrassed. "Er...sorry" he muttered and hastily walked from the room, closing the door behind him.

-End of flashback-

Grace's cheeks flushed a deep shade of red. She didn't want to answer the question. She didn't know how she felt about Steve; all that she knew was that she liked how their relationship was now, and she didn't want to do anything to ruin it. She had just got the life she had always wanted. A place that felt like home, a family. But what was the rule? Last in, first out. If she let herself fall for him and then messed things up, she would be the one to lose it all and be on her own. She couldn't let that happened, she never wanted to feel alone like that again and if that meant sacrificing whatever could be with her and Steve then so be it.

He was still waiting for an answer, expectance in his eyes, "Um...race you?" she said quickly as the lift doors slid open, sprinting down the street, away from him and away from the question. Rolling his eyes he ran after her, easily keeping up with her slower pace. Stopping to catch her breath Grace placed her hands on her knees, bending over slightly. Laughing, Steve turned and ran back to her.

"I think I need to cut down on the brownies," She stood up straight smiling half-heartedly "I'm pretty sure I saw grandmas and one-legged people passed me back there," joked Grace fanning her face.

Laughing, Steve said, "Don't be too hard on yourself. You'll be just as fast as me when I'm done with you."

"I'd rather stop time and get a head start I think," She said winking at the man who was chuckling softly at her.

"Don't you dare," He replied with a grin.

They both slowly jogged around, Steve virtually walking next to the girl who much preferred basking in the summer sun that was peeking through the sky-scrapers, a genuine smile on her lips. He gazed at her as they walked up the steps of Stark tower climbing into the lift.

"You know, I really love this city," She said, looking out of the window. It really felt like a home.

Steve nodded at her, "Yeah, it is the best city in the world. I grew up here and in Brooklyn, I have so many memories of this place." She said, feeling nostalgic as he too looked out of the city which had changed so much from what he knew as a kid.

"Of getting beat up?" She remembered reading his file about the boy he had once been. Though he had changed on the outside, he knew that Steve was still that same person. Kind, caring, brave.

He grinned slightly, "Yeah, of getting beat up. A lot."

"You were being brave Steve. You still are, everyday." She spoke with sincerity as she smiled genuinely.

The lift flew past floor after floor until they reached the floor of the gym. Grace frowned, expecting to be able to go and take a quick shower after her run.

Steve smirked, seeing her expression and said, "Come on! 30 minutes of training and then I promise to let you go."

"Says the super soldier who doesn't get tired," she groaned and he took her hand and led her to a punching bag. Grace fastened some small punching gloves around her hands, and Steve held the bag as she started to lightly punch it. "Hey I've got a joke," She announced, smiling slightly as she began to tire out. Steve nodded for her to go on, "What do you get if you cross Captain America with the Hulk?"

"I don't know," Relied the super soldier, cocking an eyebrow as she continued to hit the bag.

She winked, "The star-spangled Banner," Was the punchline, a grin on her lips. It widened as she earns a chuckle from the man, and she started punching harder, wanting to show Steve that she was strong.

"Come on Gratia!" He said, using her hero name which urged her on. Smirking she hit harder and harder and, surprisingly, Steve actually had to start pushing back on the bag to stop it from flying off it's hook. With one final punch the bag burst, spilling sand onto the floor. Both Grace and Steve looked down at the sand, astonished by her surprise outburst of strength.

"I…" She stared at the bag for a moment, "Does that happen a lot?" She asked and Steve looked up to see fear in her eyes. Her bottom lip was almost shaking by this point so he didn't say anything that would worry her further.

"See I told you that you were getting strong!" he smiled, omitting to say that there was a difference between humanly strong and splitting a punch bag. "It has been a long day" he finally said, trying hard not to overthink the broken punching bag, "Hit the showers kid."

Grace smiled at him and jogged towards the lift, leaving Steve to clear up the mess she had made. As she reached the lift and the metal doors closed behind her, she leant against the wall taking a deep breath. Where had that power come from, she thought. She took another deep breath. She didn't even know what she was capable of anymore. She was afraid. Afraid that she could hurt the people around her. Afraid that she had caused the destruction in her dream. Afraid of herself.

Steve bent over, gathering up the spilling bag when he heard a quiet laugh from over his shoulder.

"Getting a little worked up were we Capsicle," said Tony as he stopped on his way up from the garage, wiping oil off his hands with a cloth as he gestured towards the broken bag.

"Actually no," He said, standing up to address the billionaire, "Grace did this."

"Well that's new," said the older man, walking to inspect the mess.

The Captain fidgeted nervously, "Do you think this could be another power?" He asked, thinking worriedly about the girl he had developed a strong bond with.

"Could be" said Tony nonchalantly, "Maybe she used to be a boxer," He suggested jokingly and Steve gave him a look. Tony went on. "I wouldn't rule anything out with her. We have no idea what we're dealing with…best not to overthink it. She's a good kid, it's probably just adrenaline." He didn't want to let himself doubt the girl. She was his best friend, she could handle whatever came her way.

Steve thought about the possibilities. They barely knew anything about Grace's past, and he didn't want her to end up with more power than she could control. He tried to shake the negative thoughts that had crept into his mind and went to take a shower.

Getting out of the lift, Grace walked into her room to see Steve sitting on her bed. How had he got up there so quickly? The expression on his face was unreadable as he got up abruptly when she walked in.

"What are you doing in here?" she said sharply, annoyance evident on her face but it softened when she saw his now worried expression.

"Come with me quickly," he said, roughly grabbing her hand and pulling her back into the lift at the end of the corridor.

"Where are we going? What's happened?" She questioned worriedly as his grip on her hand tightened. As the lift glided to the bottom floor he grabbed her hand pulling her towards the front door of the foyer. As they did so, they bumped into Dr Banner and Steve gave him a dark look. Pushing past him, Steve dragged her to the pavement where a black van pulled up next to them. His eyes were not the brilliant blue she knew and she immediately tugged her hand away from his grip.

"Tell me what is going on," she shouted at him, trying to stay as calm as she could. Suddenly a blue light surrounded his body and his features suddenly changed into that of a woman she had never seen before.

"What the-" whispered Grace as she felt a sharp stabbing in her side. Her vision immediately blurred and her whole body swayed slightly, the world around her spinning.

"My name is Rebecca," the woman's voice echoed through her head as she emptied the contents of the syringe into Grace's body, and two men carried her into the back of the van. Getting into the passenger seat the woman drove away.

Bruce Banner creased his eyebrows together as Steve rushed through the front doors of Stark tower, pulling Grace behind him. His eyes followed them as he looked out of the window of the foyer, and he saw ' Steve' transform into someone else, a woman. He only had a moment to mull in his bewilderment before seeing two large men shove Grace into a black van. He sprinted to the lift and pushed the button for the top floor, his breathing quickening. He willed himself not to hulk out right now. He needed to help Grace and that was not the route he wanted to go down.

Steve pushed his hand through his damp hair and stepped out of his bathroom. The shower had really calmed him down, and he began to think that Grace was going to be okay. Of course, she was. They all knew how strong she was, but she just didn't see it. They needed her more than she knew.

Natasha Romanov sauntered passed his room but stopped and looked at him with a puzzled look, "Didn't you just go in Grace's room?" She questioned, confused as to how he could be in two places at once.

He looked back at her, also confused and said, "No. I went to the gym with her then took a shower."

Just then, the lift opened with a ding and Bruce leaped out telling the two Avengers what he had seen. He was out of breath, still in shock. Quickly Steve threw on some clothes and ran back to the living room where all the Avengers had now gathered. Each looked around at each other, a million thoughts running through there minds. This had never happened before to anyone on the team, and they had no idea what they were dealing with and why Grace had even been taken. She had only been part of the team for a short time, less than a year, but she had easily found her way into their hearts. Their worlds would fall apart if anything happened to her.

"What are we going to do?" Said Natasha, looking out of the window, almost looking for the van containing her friend. She should have protected her, Natasha thought to herself, she should have been there to watch out for her just as the blonde did every day.

Bruce was sitting on the plush sofa with his head in his hands, "I should have done something. I should have known it wasn't Steve," he muttered, guilt washing over him.

Thor looked over to him, placing his strong hand on the man's shoulder, "You are not to blame Banner. Grace will be found," He said reassuringly with a confidence that made Bruce have hope.

Steve walked to Grace's piano resting his hand on a key, his eyes saddened as the note rang out, 'There is no point moping around,' He thought and snapped into action.

"Right. Tony, get Jarvis to check the security footage from the camera at the front of the building. With any luck, it will show a number plate and the kidnappers. Look for any distinctive logos or patterns on the vehicle or on the clothes of the people." He added, thinking back to his time fighting HYDRA. "When you find the number plate, track it and also track Grace's phone. If it hasn't been destroyed we should be able to find it. Natasha, Clint, check out the woman's face, we might have encountered her before and she might be on the S.H.E.I.L.D database, if not that then the index. Go." He said as the team sprung into action, Tony conversing with his computer system Jarvis and clicking around on numerous computer screens with Dr. Banner in tow. Natasha and Clint had sat down in front of a monitor, searching the database for the face of the kidnapper.

Steve paced around the large room, in a quiet state of panic. He walked over to the computer screen and watched the kidnapping clip. He was surprised to see himself pulling Grace to the pavement and his stomach turned: he would never be that rough with Grace. Suddenly the person transformed into a woman. She said something inaudible as Grace was injected with some kind of knock-out serum.

"Wait. Go back," said Thor from next to Steve and the clip was rewinded to the part where 'Steve' changed into the menacing woman.

"Alter-ego Cap?" Asked Tony, trying to make the best of a bad situation but his smirk dropped when Steve death-glared him.

"I have seen this before" muttered Thor, squinted his eyes slightly.

"An Asgardian?" Asked Bruce, taking his glasses off.

"92% match" yelled Natasha from behind a computer. The other Avengers crowded around the monitor which contained a S.H.E.I.L.D file.

"Rebecca Thorne" said Clint pointing at the file. "She can transform herself to look like anyone she wants."

"Much like Loki." Thor mused for a moment, raking his brain to think why the image looked familiar. Then he noticed the unnatural blue glow of the woman's iris.

"She's good, worked with Coulson for a bit. She was put on the index but before that she was just an agent," She read further, "She was dismissed from S.H.E.I.L.D after what happened in New York due to mental instability." she finished, clicking on an official image of the woman.

"But why does she want Grace?" Said Steve, puzzled.

"I don't think it is she who wants Grace," said Thor, zooming in the image to her unnaturally blue eyes. Clint shivered, remembering when he had possessed those eyes. Thor knew his assumptions had been correct, and he shuddered. He didn't even know what his brother was capable of anymore but he knew one thing. He needed to get Grace back and get Loki back to Asgard.

"Loki." Murmured Steve. Loki was unforgiving and mischievous and the pain of having left Grace alone, having not been there to protect her, intensified: he feared the worse.