A/N: I don't own the Avengers; those guys belong to Marvel, unfortunately. It would be wonderful if I had my own personal Captain America but I only own the plotline and Gwen.

Edit 12/28/2015: I'm returning to this story after almost two years! I'm making a few edits to keep everything semi-current with the Marvel Universe.

Edits: Mostly grammatical errors that I missed before. The story now starts in 2013, post Avengers and pre- Age of Ultron.

Chapter One

Mother Earth

The Earth breathes. She feels it, as it moves and shifts. Every inhale, every exhale, is etched into her thought. The warm crust cocooning her body slid, and cool air hit her back. Her eyes opened, and she felt surges of power that she had not felt for almost twenty years.

The pull returned to her core, and the rocks tightened around her once again.

A cool, female voice rang throughout Avengers Tower. "All current members affiliated with the Avengers Initiative are to report to room 4B for debriefing." Tony Stark rubbed his temples. The acoustics in his newly renovated workshop made the normally smooth prerecorded message sound jolty and hollow. He ignored the summons and continued to tinker with the small circuit board in front of him. Small sparks burned his fingers as he poked and prodded the chips and wires. It had moved beyond the need to fix dummy (yet again) and now he was just keeping his mind busy as he tried to ignore the nagging feeling on the back of his neck.

"Tony," Pepper Potts stood in the glass doorway leading up to the first floor. She had her arms crossed. "Did you really think they were going to let you skip out on your first mission since New York?" She had a slight smile on her face, so Tony knew she wasn't really mad. He just threw his hands up in a shrug.

"It was worth a shot, anyway," He sighed. He grinned and Pepper rolled her eyes.

"Just get up there. I have to leave for an interview with a prospective client soon, so I can't take the wrap for you again." She leaned out the door and Tony watched her as she walked back up the glass staircase. Man, he was lucky. He grinned and propped his hands behind his head. That is, of course, before he remembered all of the burns and promptly cursed everything from the trees to Director Fury, and shot up from his seat.

The conference room was quiet. Director Fury stood staring at the wall behind the table that five of the six Avengers were seated. The large television behind him remained turned off. Thor sat in a relaxed position slid halfway down his chair. He picked at his fingernails and then sighed and looked at the wall opposite of Fury's fixation. Thor? That was weird, Tony was sure that the demigod was still in Asgard. He'd ask later. Clint and Natasha sat rigidly in their chairs, neither looking around the room or at anyone else. Bruce pushed his glasses up his nose and shifted in his seat. Steve glanced at his comrades and sighed. An awkward few more seconds passed before Tony cleared his throat to signal his arrival. Fury addressed the latecomer. "Mr. Stark: So pleased that you finally decided to join us."

"Yeah, well, I figured what's a party without the entertainment?" Tony sat down next to his large Asgardian comrade. Thor nodded in his direction before turning back to the Director.

"Very cute. Now, if you will all turn your attention towards the screen," Fury clicked a button on the small remote he was holding and the television showed a picture of a young girl, aged no more than 10 or 11. She had dirty blonde hair and tanned skin. Her face showed no emotion. The thing that Stark noticed most, however, was the look of intense rage on the child's face. It looked out of place on someone so young, like she was doing everything in her power to keep from murdering the camera lens.

"This girl may not look like much, but don't let that fool you. Her name is Gwendolyn Nicholson. She was one of the most dangerous subjects on S.H.I.E.L.D.'s radar eighteen years ago." Fury paused to switch the screen to a video of the young girl. Before he could play it, Tony's hand shot up into the air. Fury sighed and nodded in his direction.

"Um, yes, while I am sure that this kid is some sort of crazy dangerous, why do we care about old news? I mean, didn't you guys nuke everything that was a potential threat back then?" Tony placed his head on his head and crossed his legs. He just couldn't resist pushing the Director's buttons. "I mean," He continued, "Y'know." Steve slapped him upside the head.

Before he could protest, Fury cleared his throat and turned to the screen and hit the play button.

The video was grainy, but it was obvious that it was being filmed in some sort of testing facility. Three men in white hazmat suits were holding clipboards and looking into some sort of chamber. One wall was glass, but from what the team could see, the rest of the room was nothing but white concrete. There wasn't even a bed. The film flickered, and then the scene switched to show a young Gwen Nicholson, probably age six or so, sitting in the middle of the empty white room. She held her knees close to her torso, and stared at the ground in front of her.

"Now Gwen," A voice crackled through an intercom, "Can you behave long enough for us to bring you something to eat, sweetheart?"

"Don't call me sweetheart." Gwen's voice came through distorted, but it didn't sound fearful- more bored or tired. Bruce leaned closer to the screen as Gwen straightened her legs. As she stood up, he noticed a small waver, almost like a heat wave, surrounding her tiny body. It became softer and softer, until finally it disappeared. Bruce removed his glasses. He cleared his throat and the Director paused the video. Bruce waited a second, and then spoke.

"Director Fury, do I need my glasses cleaned or was there something around her? Like a-… a shield? Or a force field?"

The director played the video again and responded, "Wait a few seconds, and you'll see."

The clip continued, and a small door opened in the white room. One of the hazmats walked in carrying a plastic tray of food. It jolted from his hand quickly, and froze in mid air. It didn't float; it just stuck there, almost like it was placed on an invisible table. Then, it flung itself toward the girl before orbiting her like a satellite. Nothing was spilled. The camera clicked, and then continued what appeared to be years later. The Gwen on the screen matched the picture the team was shown minutes previously. Her dirty blonde hair was longer and slightly waved, and she looked much better fed. Steve noticed that while there was still no bed, Gwen was surrounded by stacks of books. She was wearing a white hospital gown with some sort of pattern on it.

"Gwendolyn,"The same voice crackled over the intercom, sounding stressed, "We have tests to run today. Will you behave?"

"No," She responded. Bruce scoffed. Well, at least she was honest. Fury shot him a look and he focused his attention back on the screen.

"Gwen," The intercom cackled, "I do not believe you are in the position to be misbehaving."

"I'm in the position to do whatever I please."

Then the screen flashed white, and the clip ended.

The team sat for a minute before Tony gracefully broke the silence. "What the hell?"

Fury responded to the philanthropist's question, "That is the last data record we have from subject Gaia, as she would come to be known."

"Mother Earth," Banner responded.

Fury nodded at the quiet scientist. "Correct. That field you noticed, Mr. Banner, is the subject manipulating the gravity around her into a nearly solid form. She can repel almost anything at speeds faster than most of your cars, Mr. Stark. She can also attract objects of small mass to her, and use them as shields. More than once she was shown to use the ground itself as a barrier, creating her own gravitational field around her and forming a crust and a mantle, if you will. She turns her body into a miniature of our own earth's core."

He paused, and Natasha repeated Bruce's earlier observation. "Mother Earth," she said with an amused tone.

"Do not be fooled by her appearance in the video, team. She is more dangerous than many gave her credit for, and so she escaped. That day subject Gaia sank herself into the Earth, through multiple layers of concrete, steel, and iron. She hasn't been heard of since, and ten years ago she was labeled as terminated."

Thor straightened and placed his hands on the table. "But she is not terminated, yes?" He addressed Fury, "That is why you have gathered us, is it not?"

"Speaking of which, didn't expect to see you so soon, big guy!" Tony exclaimed. He playfully slapped Thor on the back. The demigod gave him a grin that didn't quite reach his eyes.

"Are you done?" Director Fury quipped.

"My apologies," Tony responded with a wave of his hand. The Director ignored the sarcasm in his voice.

Fury turned back to the screen and clicked his remote. A map of Australia appeared on the television.

"Two days ago a strange pulse emanated from somewhere in the Australian Outback. The pulse is nearly identical to the one recorded the day Subject Gaia escaped. The local news is chocking it up to a small earthquake, but our technology and previous knowledge suggests otherwise. The frequencies don't quiet match up, this one is definitely stronger than the one felt upon Gaia'a disappearance. But it's close enough to warrant an investigation. Now, that being said, this is simply a reconnaissance mission. It is not needed for all of you to fly out to Australia. I have chosen Dr. Banner and Agent Romanoff to investigate."

"Woah, woah, woah, there, Popeye," Tony interrupted, "Don't get me wrong, but are you sure that's a good idea? I mean, they'd have to use an airplane and that's just, you know, company resources right there. Not to mention," He paused, "What happens if this Earth girl decides to just, you know," He made a "zip" noise and crushed his hands together. "I don't like it."

"Thank you for the concern, Tony, but I'm sure Dr. Banner and I will be just fine on our own," The Black Widow responded a little bit blandly. She knew the philanthropist felt cooped up in his little workshop, but she wasn't going to let him take away her first chance back into the field.

"Not to mention," Fury interrupted sharply, "If my assumptions are correct, Gwen Nicholson has not seen a human being for almost twenty years. It would be better if we send a woman and someone who isn't going to try and seduce her or shoot her with an arc reactor blast,"

"Hey now! I am in a committed relationship-"

"And no offense to you, Captain, but she is old enough to know who you are. It might be a little off putting to send a super soldier in to what is supposed to only be an intelligence mission," Fury continued, ignoring Tony's protests.

"Duly noted," Steve responded.

"The assignment is to go in, find out what you can, and if the girl decides to cooperate, bring her back to base so we can figure out what the hell is going on. Agent Romanoff, Doctor Banner: I suggest you start packing. You leave tomorrow morning at precisely 7:30 am. Good day, Avengers."

With that, Director Fury swept out of the room. Bruce sat in his chair rubbing his temples. It wasn't that he resented the mission- he loved finally doing something- he just wasn't sure how well he and Natasha would work together. Besides the Avengers, they had never even fought in the same vicinity. Of course it made sense: Banner the scientist and Romanoff the woman (roughly). If anything strange were happening, he would pick up on it. And The Black Widow was known for dealing with sticky situations. If this girl was as unstable as Fury seemed to imply, then she might respond better to someone of her own gender.

Clint had been strangely quiet throughout the entire briefing. So had Thor, but Thor was focused on finding Jane- it was expected. Bruce had a feeling that it had something to do with the woman he was assigned to investigate with. Someone squeezed his shoulder as they walked behind him.

Bruce looked up and realized that everyone else had left the conference room. He had gotten lost in thought again. Oh well, he thought, not like anyone ever notices anyway.

The next morning Dr. Banner and Agent Romanoff climbed in the super helicopter destined to take them to the land down under. They didn't bring much. Banner brought a change of clothes, a pre-powdered toothbrush, and a ballpoint pen. The clothes were just in case The Other Guy decided to show up, and the toothbrush was because, well, Bruce Banner was a stickler for hygiene. Agent Romanoff brought only her S.H.I.E.L.D. uniform and her weapons. She was currently dressed in civilian clothes -A simple white tee shirt and dark gray cargo pants, which privately Bruce thought made her look even more intimidating. She looked too innocent. She had too many pockets to hide weapons. Seeing her this way, it almost made sense to Bruce how many of her opponents underestimated her. Almost.

The ride took four hours. The Avengers were given nothing less than best, and apparently that meant military grade air travel. The closest airport was over 300 miles from where the epicenter of the strange vibration was thought to have been located, so the only option was parachuting down into the wild outback. Banner fastened his goggles and secured his back pack, and then looked down.

Man, was this not going to be fun.

He barely had time to take a breath before the pilot yelled something and he was shoved out of the chopper.

Not fun at all.