A/N: Should this go in the crossovers? I don't think it should, as I have no characters from His Dark Materials, only the Daemon idea...

This was inspired by some prompt or another I ran into at Avengerkink, but I can't remember what the prompt was or who prompted it. So yeah...

Anyway... the basis of this AU is pretty straightforward- like in His Dark Materials, people have daemons. It isn't necessary to read His Dark Materials to understand this, only to know what a daemon is. Basically- they represent the person's soul. Everyone has one, and through childhood they can shapeshift into whatever, but when the person hits maturity the daemon settles into a form that represents the human's character. If you don't know what a daemon is and want to read this anyway, and don't understand something, I'll be happy to explain.

Disclaimer: I don't own the Avengers, any of the characters from the movie, or the idea of daemons.

Prologue

"This is ridiculous. Panthers don't just appear from out of nowhere." Nick Fury stated flatly into the phone. Granted, he had come to accept the impossible in his years as director of SHEILD, but this…

"Begging your pardon, sir, but this one did." Selvig insisted. "Right in the middle of the lab. Practically magic." For what might have been the dozenth time, the director found himself wondering whether hiring the scientist had been a good idea. His brilliance and his friendship with Thor were both valuable assets, but he had proven prone to superstitions and belief in the supernatural. Add that to his annoying habit of referring to the tesseract, which he studied with diligence, as a "she", and the result was a constant chafing on Fury's nerves.

Fury was well practiced at hiding his annoyance, but at his side, Kenara gave a low growl. Raising a single eyebrow, he placed a warning hand on the flank of the grizzly bear. His daemon had all of his anger, but none of his patience.

"So what you're saying, Selvig," Fury attempted to organize his thoughts, "Is that a panther just materialized in the middle of your motherfucking lab."

"Exactly, sir."

He sighed. There were no peaceful days at SHEILD. Not that he would have it any other way, of course. "I'm on my way. Is Barton there?"

"He is."

"Good. Tell him to contact agent Romanoff. And don't let anyone touch that creature until I get there."

Natasha was used to unusual calls in the middle of the night. It was part of her job, after all. These calls, however, usually didn't involve panthers.

"This is stupid." Raskanor muttered in Russian as the assassin blinked the sleep from her eyes. He hung from the ceiling by thin webbing, swinging back and forth mere inches from her face. Raskanor's form matched her codename- a black spider with a red mark across his swollen stomach.

Anyone who observed her daemon could easily recognize he wasn't a true spider- he was easily the size of a tarantula, and his hourglass mark was generally not found in males. But he was perfect for the type of jobs they were usually sent to perform- he could go most anywhere unnoticed, overhear bits of conversation… and his sting was just as lethal as that of any black widow. In the time she preferred to think of as before, when she had still worked for the Russian government, Raskanor had been encouraged to break the taboo preventing a daemon and a human that was not theirs from touching. Nowadays, both of them preferred to avoid that particular skill of his.

It took Natasha less than ten minutes to wear her SHIELD uniform and make herself look presentable with slight touches of hair crème and makeup. It might have taken her even less if not for Rask's endless commentary.

"Absolutely ridiculous," he continued his train of thought, "magical panthers? They should put that Dr. Strange guy on it, not us. We don't do magic. We don't do panthers either. Maybe they should call Central Park Zoo or something."

Natasha sighed. Her daemon's talkative nature clashed painfully with her own stoic behavior. "Director Fury said this was important. If he says it's a job for us, then that's what it is."

"How about we sleep in? Take a day off? Not show up today? I don't think we've ever done that. There's always a first, right?"

"What's your problem?"

"Nothing. I just don't feel like dealing with teleporting cats at…" he swiveled towards the digital clock at her bedside, "3AM."

"You can sleep on the way. I'll wake you when we get there." Rask grumbled softly, but swung onto her shoulder, taking care not to leave any webbing on her clothes (oh, she hated when he did), wrapped his legs around a strap on her collar, and went to sleep. Natasha knew he hadn't slept all night- it had been man, many years since they had slept at the same time. Watching their backs had become second nature.

Natasha pulled on her black leather boots, grabbed her key, and locked the small apartment behind her. She had been living there for nearly a month. It would soon be time to move.

Deija saw Natasha enter the enormous lab before Clint did. For all his reputation as Hawkeye, his eyesight couldn't compare to an actual hawk's. The sight of his old friend and ally after weeks, if not months, without seeing her sent a wave of excitement through his chest, but none of it showed on his clam face.

Deija fluttered from their perch over the door and hovered a few feet away, near the limit of the distance they could maintain between them. Raskanor scuttled across the wall (a slightly longer distance than Deija could manage- Natasha and her daemon were able to maintain a longer distance than Clint and his own) until the two daemons were eye-to-eye with each other.

"Hey," Raskanor greeted.

" 'Sup?" Deija replied, and Clint could hear every word of the conversation as though here were standing right next to them, despite the fact he was 80% deaf.

"Oh, the usual- waking up at ungodly hours for the director's latest whim. So, do you mind explaining what's going on here exactly?"

As they talked, Clint cast his gaze around the lab. It was packed with computers, machines, and technology he couldn't even pretend to understand, as well as scientists, and lots of them. For once, though, their attention wasn't focused on the tesseract, which was placed in a machine in the center of the room. Instead, they were all crowded around a dark shape on the floor.

"We're not sure, really." Deija admitted. "She just appeared in the middle of the room, right under the tesseract. Hasn't moved since."

"She?" The spider inquired.

"We think she's a daemon."

Deija's words made Natasha shudder involuntarily. If the alleged panther was a daemon…

"Where is her human?" Rask voiced her thoughts.

"We don't know. It's impossible. But there she is, and she hasn't talked to anyone yet."

"Then how do you—" Her daemon was interrupted by director Fury, who stepped away from the crowd of agents and scientists and turned towards her. Rask dropped back to her shoulder, and Deija swooped over to Clint's.

"Agent Romanoff." He acknowledged her presence, and Kenara grunted in Rask's direction. "Has agent Barton briefed you yet?"

"Roughly, sir."

"Right… to sum this up, a panther daemon materialized here roughly an hour ago. She's barely conscious, and there's no human in sight. I want you to get anything you can out of her. Who is she? Why is she here? Where the hell is her human? Am I clear, agent?"

"Very clear, sir." Natasha made her way towards the gathering, and the employees let her pass. She wasn't a common sight around this particular base, but among the agents of SHEILD, her reputation preceded her (most of that reputations was "classified", which earned her some respect in itself. A clear path opened before her, and she finally caught sight of the strange daemon.

Lean and muscular, she was slightly smaller than an average panther, with sleek black fur that looked as if it had been regularly taken care of, but suddenly abandoned and allowed to grow disheveled. As Natasha approached the seemingly unconscious creature, a pair of yellow, feline eyes opened to slits, and a soft warning growl escaped the panther's lips.

Using the same approach she would use for a wounded animal or frightened child, Natasha crouched to appear less intimidating, and advanced no further. Instead, Rask scuttled down from her shoulder and onto the cold floor, coming to a stop by the other daemon's head.

"Hey," he said in a soothing voice that was so soft Natasha doubted anyone but she and the panther could hear. "Don't be scared. We're here to help you."

A single word escaped from the panther's lips, barely more than a whisper. "Why?"

"Because you look like you could use our help." She didn't respond to that statement, and Rask decided to use a different approach. "Where is your human?"

"My…" A hint of confusion. "I have no human." A chill ran down Natasha's spine, worse than how she felt when she realized there was no human in sight. There was no such thing as a daemon with no human.

"Of course you do." Rask insisted. "Try to remember. That woman over there, with the red hair," he waved one of his legs at Natasha, "she's my human. We're bonded. We're two parts of the same person. So where is yours?"

"Mine… he… he left…" the creature's voice broke. "He left me… tore me away… he's gone!"

"It's no use, sir." Natasha told Fury quietly, fifteen minutes after the conversation had started. "She won't say anything else. Only that her human left her, and that she's alone. She doesn't know her name, or at least she won't tell us. I don't think she's sane, sir."

"I don't understand." Selvig interjected, overhearing their conversation. His daemon, some golden-brown furred rodent that Natasha could not identify, curled around his neck, exuding more anxiety than Natasha had known a daemon was capable of showing. "How can a human separate themselves from their daemon?"

"I'd be damned if I knew, Selvig. What I want to know is why did she materialize in our lab, of all places?" Fury inquired.

"I have a theory." The scientist mused, "The Tesseract is an energy source, right, and a portal. A doorway in space. So, hypothetically, if she was to materialize anywhere, why not here? She could have been drawn to the energy, and passed through the door."

"But what why did she materialize at all?"

"Your guess is as good as mine."

In a corner of her mind, Natasha could still hear the conversation going one between Rask and the unnamed daemon, and the panther's nonsensical response- a plea muttered over and over again. "Come back… come back…"

A/N: So? Did you like it? Comments? Criticism? Read & Review!