This story takes place during the events of The Avengers in which I just added Katarina and the plot points surrounding her. I hope you like it! Please feel free to tell me what you think (good, bad, constructive criticism). Thanks for reading :)

The Tesseract has awakened. It is on a little world. A human world. They would wield its power, but our ally knows its workings as they never will. He is ready to lead. And our force, our Chitauri, will follow. The world will be his. The universe yours. And the humans, what can they do but burn?

Katarina Sunderland smiled sweetly over her Styrofoam cup of weak coffee.

"The usual. Probably childhood emotional trauma, uncaring parents or highly successful siblings."

The detective glanced up from his notebook. "He was in and out of the foster system since he was four."

"Figures. At least make it difficult for me, Watson." Katarina yanked on her braid that fell over her shoulder. "Was one of the victims a foster parent?"

"No…but one of the young women was in the same foster family for a few years."

Katarina's smiled turned wicked. "Adopted before he was, huh? Typical. She was the intended victim. The others were just casualties."

The older detective narrowed his eyes from behind his wire-framed glasses. "He killed twenty-two people in this office shooting. Why not just the woman?"

Katarina shrugged, completely bored.

"Not our concern, now is it? That's for him to worry about behind bars. Unless they of course inject him, which would be my vote by the way."

The detective glared at her with unabashed disgust. "Murder is never the answer, Miss Sunderland."

Katarina, who knew a handful of professional assassins, could only nod with a false look of remorse. "Of course, sir. My apologies."

The phone rang loudly and Katarina thankfully jumped for it, twirling a pen in her other hand. It was a long Tuesday afternoon in the office and she was just as bored with this job as she was when her godfather had insisted upon it. She had other plans, in due time, when her godfather wasn't quite so protective. Katarina had begged dozens of times to work for him and his company, but he insisted this would have to do until the chaos died down.

"Miss Sunderland. I have an assignment for you of the utmost importance. When can you leave for New York?" a familiar, gruff voice inquired.

"Well, Fury," Kat grinned like a Cheshire cat, "immediately."

"This will be a hopefully brief assignment but it must be taken care of. We have only encountered this once before, but it isn't what our profilers are used to. Your room will be set up in Stark Towers."

"Oh, Tony didn't tell me they had finished construction," Kat mused.

Fury continued as if she hadn't spoken. "Your professional skills are unparalleled, as Tony has told me."

"Did you get his permission for me to be brought on to this case?"

Fury laughed, a short bark. "Does it sound like I ask for permission, Miss Sunderland?"

"'Course not, sir. Who am I dealing with?"

"You'll see when you get here. Romanoff will brief you."

"Will Clint be with her?" The two were kind of a package deal when Katarina got involved with the organization. Both had trained her in hand-to-hand combat, survival skills, and other elementary assassin essentials.

"Barton has been compromised, Miss Sunderland."

Oh…poor Natasha, Katarina thought, frowning for the first time during the conversation.

Kat glanced up at her computer screen. "Does this have anything to do with the psycho loose in Germany?"

"It does indeed."

"Looks like Tony and Captain Rogers had it all under control." She scanned the article quickly. "Asgard. Isn't that where-"

"We will brief you upon your arrival, Miss Sunderland. Highest levels of security and all," Fury said with a distinct tightness to his words. Kat knew better than to continue. "Do you accept the assignment, Agent Sunderland?"

Katarina loved the sound of that. "Count me in, Fury."

Pepper Potts's heels stuck the polished floor as she marched down the corridor, Katarina at her side. Pepper was two inches taller than Katarina, and her heels made her far taller. Katarina's black leather boots made soft echoes of Pepper's steps.

"So, what do you know about this guy?" Katarina inquired as they walked in companionable silence.

Pepper sighed, her eyes worried. "I know Tony certainly isn't his biggest fan."

"I can't see Tony being a big fan of anyone but himself," Katarina chuckled.

"True. But you see my point. He's seriously bad, Kat. Be careful with this one," Pepper warned.

"I'm always careful," Katarina said, flashing an easy smile.

She approached the door at the end of the hallway and punched a code into the keypad beside the door. The chrome door slid away, revealing a conference room. The panoramic view showed the clouds and blue sky of the floating headquarters. A long, black table furnished the room, surrounded by familiar faces.

Natasha Romanoff jumped from her perch on one of the chairs and rushed Katarina. They playfully tossed a few punches that didn't connect and twirled and flipped around the room. Katrina finally stopped, letting Natasha crash into her. They embraced, laughing loudly.

"Oh, god," Tony Stark muttered. "My least favorite tag-team is reunited."

"I could say the same for you, Stark," Katarina shot back.

He frowned. "Me and…?"

"Your ego."

"Ah, of course. How could I forget such a dashing, young fellow?"

Kat giggled and released Natasha long enough to embrace Tony. He was handsome, in a rugged familiar sort of way. His dark brown hair was cut short and his facial hair was impeccably trimmed. He was wearing a tight red t-shirt with a black logo for the band Guns 'N Roses on it.

"Who's this guy who kicked your ass?" Kat inquired.

Tony scowled. "He didn't kick my ass."

"Yes, he did. He kicked both of our asses," Captain Steve Rogers admitted.

Katarina kissed the young blonde man's shaven cheek and shook her head.

"Then we will have to just hand his ass to him."

"That's the spirit!" Tony whooped loudly.

Steve rolled his blue eyes with exasperation. "You all are incorrigible."

"Big word, Captain," Katarina teased.

"I'm not incorrigible," Doctor Bruce Banner protested.

"You're a genius," Tony agreed. "As am I."

"It's not all about you, Stark," Natasha said, rolling her eyes.

Tony looked thunderstruck. "It's not? Says who? I didn't agree to this!"

Steve slugged him in the arm. "I say so."

Katarina shook her head.

Captain Steve Rogers was gorgeous. He could look at a girl with those beautiful blue eyes and have her melt into a puddle. He was blonde and had the manners of a man from another time. Which is exactly what he was. Doctor Bruce Banner was soft-spoken, with short dark hair and equally dark eyes. He rarely laughed at Tony's joking mannerisms, but Tony was quickly growing on him like a suffocating sample of mold.

"We've never actually met," Kat began, shaking hands with the scientist. "I'm Katarina."

"Tony has told me much about you. It's a pleasure," Bruce replied with small smile. Kat noticed that even when he smiled his eyes retained their quiet sadness.

Nick Fury sat silently in one of the chairs, his hands clasped in front of him. He was dark-skinned and bald, with a patch over one eye. He watched the world's most skilled profiler mill about with her friends, laughing. She took her work very seriously, he knew, and she would have to keep her head for the job ahead of her. If anyone could uncover the invader's motives and next move, it would be this young woman. The fate of the world quite possibly rested on the shoulders of a nineteen year old.

"Miss Sunderland," he greeted the young woman.

Katarina straightened and unlinked her arm from Natasha's. "Fury," she replied with a polite smile.

"Are you prepared for your assignment?"

His words hung in the suddenly silent room.

Katarina stepped forward, her head held high.

"Of course, sir. What do I need to know?" she answered, her voice steady and sure.

Fury stood up to his full height that towered over Katarina. His eyes searched hers.

"He's the God of Mischief. The God of Lies. This is not a job to be taken lightly, Agent Sunderland."

Katarina didn't speak. Nick was going into 'lecture mode' as Tony had called it on several occasions. Katarina was listening intently, leaning forward on the table, her palms pressed flat.

"He wants to take over our world, to enslave the human race. Our Avengers Initiative had congregated to stop him. He has been captured and is in our custody."

"How did he get here?" Katarina asked.

"Portal, as far as we know. He's Thor's adopted brother."

Katarina frowned. The limited knowledge she had of the Norse god gave her enough to form a profile on Thor. This didn't match up, but then again she knew how different siblings could be.

"He has control over Clint Barton and Doctor Erik Selvig of New Mexico."

Katarina glanced at Natasha out of the corner of her eye. Natasha looked away quickly.

"What do you want me to do with him? He sounds pretty evil. It doesn't sound like you need me to tell you that," Katarina pointed out.

Fury nodded in agreement. "We need you to figure out what he plans to do next. We need to know his weaknesses, his strengths. Find out anything and everything you can, Agent Sunderland."

"I'll take her to him," Natasha volunteered.

"As will I," Steve agreed.

"Good. Meet up with Thor after. You might need his insight," Fury advised.

He dismissed them all with a wave of his hand, and the group dispersed. Tony, Pepper, and Bruce went up a stairwell, talking science and business. Natasha, Steve, and Katarina made their way down the corridor, weaving through several hallways. Steve led the women, chatting with Katarina.

"How is what's-his-face?" Natasha inquired, adding to the conversation.

"Mario?" Katarina cringed. "I'm so sick of seemingly nice guys cheating on me."

Steve frowned. "He cheated on you? I'm sorry, Katarina." Steve upheld honor and loyalty above almost everything else, and this news certainly rubbed him the wrong way. Had the men of this era completely forgotten what it meant to be a gentleman?

"Me, too," Kat sighed.

Natasha smiled, teasing and trying to cheer up her friend. "You want me to kill him in his sleep and pin it on the other woman?"

"As good as that would make me feel…" Katarina replied. In truth, Mario had asked too many questions and far too much of Katarina. He had talked of moving in together, a step Kat was afraid she would never be able to take.

The three laughed and it echoed down the corridor. Curiosity and nerves clenched around Kat's heart. She was about to profile a god. This was no common criminal, no average job.

"What's his name?" Katarina asked as they turned another corner.

Steve glanced at her with concerned blue eyes. "I thought you just said his name was Mario…"

"Not him. Thor's brother, Mr. Evil," she replied.

Natasha answered, her voice harsh with an unconcealed loathing, "Loki."

Loki paced back and forth in the small cell. He could see the control panel out of the corner of his eye, the lights blinking tantalizingly. His cape whipped out behind his shoulders and his hands clenched into fists. He heard the door open and the soft voices of several people talking, but he didn't look up from the floor.

"He doesn't seem so scary," he heard a female murmur, her voice thoughtful.

Loki grinned to himself. Give him half a chance and he'd show her what it meant to be 'scary.'

"Don't underestimate him," another female snapped at her. It was the pretty red-head, dressed in a tight leather suit. She was glowering at Loki.

"Ma'am, with all due respect, Katarina's a professional. She knows how to crack him," the man said. Loki recognized him as the one referred to as 'Captain Rogers.' The red-head was Agent Romanoff. The small brunette, however, he had never seen before.

Loki glanced up, his eyes meeting hers. She was short and young to this world. Naïve, trusting, mortal. Her brown eyes were dark and curious, her lighter colored hair pulled back in a twisted knot. She walked right up to the glass of his confines and stared him straight in the eye.

"Can he hear me?" she inquired, glancing over her shoulder to Agent Romanoff.

"Yeah, and you can hear him," Romanoff sneered at the man.

Loki smiled back, a chilling, sadistic look.

"We need to get a sound-proof aquarium to stick Tony in," the little brunette laughed.

Captain Rogers shook his head, smiling slightly. He reached out and gently touched the back of her arm and Kat glanced up at him. It was so nice to see the soldier again.

Loki glanced at them in disgust. It was obvious the captain and the girl were attracted to one another by the look they shared.

"Well, you guys can go now," she said to the others. She sat down cross-legged in front of Loki.

Katarina watched the tall, slender figure commence his pacing. Natasha stayed behind her, eyeing the god wearily.

"C'mon," Steve urged. "Give her space to work. We'll check on you later, 'kay?"

"See you around, Steve."

Natasha and Steve left silently. Katarina kept her eyes on Loki.

He was abnormally pale, with slicked-back black hair and delicate features. He walked with a certain grace that Katarina knew she would simply never possess. She was far too busy tripping over her own feet to be graceful. His eyes were a bright green and kept darting to her.

Loki wasn't sure what the young woman was doing. She sat there and watched him intently, her brown eyes tracking his movements.

"So…what's your name?" she asked. Her voice echoed in the almost empty room.

Loki glared at her. How could she not know his name? Everyone in this floating fortress seemed to know who he was and what he was there for. For once people knew who he was, not just 'Thor's brother.'

She cocked her head to the side. "You speak English, don't you?"

Loki almost cringed. Her voice was far too innocent to be sincere. She tucked a stray lock of hair behind her ear and pulled her knees to her chest. Loki couldn't decide how old she was. She was well-developed, like a mortal woman, but had such a quality to her that made him think she was no more than a child. Her hips and breasts were full, filling out the black t-shirt and matching leggings that adorned her body. She wasn't as thin as the assassin. Loki actually preferred the way the flesh gathered on her body, but it made her look stronger, as if more force would take her down than the Black Widow.

"You have to. Otherwise, Fury would have called in someone else. I only speak English, you see. Except for the bits of French I learned in high school." Which was a lie. She spoke seven languages fluently.

Katarina kept talking, not giving away anything too personal. The man had stopped pacing and was watching her. His expression was a mix of amusement, disgust, and confusion.

"I hear you're Thor's brother," she finally said.

The amusement left his face and the glare returned.

"You don't look like him. Adopted, right?"

Loki turned his back on her.

"Oh, the cold shoulder, huh? Very original. But, you see," she stood up and walked around the glass container until they were once again face-to-face, "that won't work. You've got nowhere to go."

Loki saw the fierceness behind her eyes and he began to rethink his original assumption that she was so naïve.

"Do you ever stop talking?" Loki felt like kicking himself for acknowledging the girl.

She beamed, clearly pleased she had made him speak. She only did so to cover the shiver that raced down her spine from her ears to every nerve in her body. His voice was smooth, measured, melodic. It was the type of voice that recited Shakespearean sonnets, not threats of world dominations and submission.

"I don't talk in my sleep," she admitted.

Loki continued to stare at her. Katarina tried not to flinch away. His eyes were such a pure, sea glass green, and they seemed to search her soul and mind. He tilted his head and took a step closer to her.

"Why would you let your comrades abandon you? Don't you know how dangerous I am?" Loki demanded.

Katarina did probably the stupidest thing she's ever done: She laughed at the god.

"I asked them to go. And they all say you're psychotic. I'm here to find out if that's true or not."

Loki frowned, his smooth brow creasing. "I'm trying to take over your realm, and you're not sure if I'm dangerous?"

"So you admit you are trying to take over this realm? Interesting… not many would admit to that. Especially if you're up against people like Iron Man and Captain America." She stepped forward. If the glass hadn't been between them, she could have reached out and touched Loki. He towered over her. At least six-foot, Katarina thought idly. If he was human, with that build, she could have taken him down with two or three blows, depending on how fast his reflexes were. Godly strength was not something she could measure, however. "You can't win, you know. There's no way you can beat them all."

Loki grinned. It chilled Katarina to the bone, and she knew right then and there that she would probably die if Loki ever escaped his cell.

"Watch me," Loki countered, his bright eyes dancing.

Katarina leaned on her toes, their gaze locked. "I guess seeing will be believing."

"Is that what you came here for? For me to unveil my plans?"

Katarina shrugged. "That was the hope. It never really goes that quickly, but I have to lead in somehow. You're very intelligent, aren't you?"

"You have no idea, mortal," he hissed, catching her condescending tone.

"But you're proud and envious, and that will be your downfall." She continued to speak as if she hadn't heard him. "Your hubris is quite impressive," she laughed.

"And your downfall is the trust you have in your heroes. They won't be able to save you, little girl."

Katarina scowled and Loki grinned in response. He had somehow hit a nerve.

"Never call me 'little girl.' I'm no child." She turned on her heel and began to walk away. At the door, she turned back to Loki and said, "And my only weakness is milk chocolate."

With that, Katarina left the God of Mischief staring as the door closed and locked behind her.