The Entropy of Sound

Marvel Cinematic Universe The Avengers (Marvel Movies) Spider-Man (Tom Holland Movies) Agents of S.H.I.E.L.D. (TV) Iron Man (Movies) Captain Marvel (2019)
F/M
Gen
G
The Entropy of Sound
author
Summary
What if, when Loki stole the Tesseract, Fury had added one more person’s file to the Avengers Initiative?The other heroes don’t know what to make of their last-minute recruit, a young woman named Riley Greene who has little experience and looks fresh out of high school.But Riley won’t let that stop her. She’s determined to prove herself to her new teammates, and hopes that by saving the world, she might finally find some sense of meaning from her tragic past.Join Riley on her first step into the multi-story Resonance saga that will span the entirety of the MCU, as she figures out how to navigate entering adulthood when you also happen to have superpowers.
Note
I can’t believe I’m FINALLY posting it!! This series has been in progress for almost a decade now, but thanks to ADHD and life nonsense, it sat around in limbo for ages. But NO MORE! The saga begins!And yes, I’m well aware that the “Avengers OC” genre of fics is way past its heyday at this point, but I wanted more for this story. Also, I will not be romantically pairing Riley with any of the main original six Avengers at any point now or in the future. (I already have planned who she’ll pair up with in the future, so look forward to that surprise.)I’ll freely admit, this technically started out as a ‘self-insert’, because I was bored during college lectures, so I entertained myself by playing around with the fun challenge of “how would I seamlessly insert myself into the Avengers without disrupting the MCU itself?”. But unsurprisingly, the character quickly took on a life of its own and the story became a separate beast entirely.This story will be Part 1 of the Resonance series, and I’ve already mapped things out all the way through Civil War, including numerous mini-fics involving characters from the many tv shows.This is also my heads up to anyone that might really dislike certain characters, romantic pairings, or story events in the canon MCU, or that really want to see different ships or events happen: THIS SERIES WILL FOLLOW CANON TO A TEE!!! I myself have plenty of personal opinions about MCU canon; things I didn’t like or would prefer to see. But the whole point of this series is challenging myself to accurately weave a new character’s story into and throughout the entirety of the expansive MCU canon timeline. So please don’t send hate about ships and stuff, that’s not what this story is about. Things could change eventually, but for now I’m operating with the MCU canon as my baseline, with the tiniest smidge of detail from the comics here and there. If this bothers you, read elsewhere.Anyway, please enjoy the first chapter! I welcome any and all feedback, comments and critiques!! Also I don’t currently have a beta, so message me if you’re interested!Disclaimers: Any and all characters and events, except for Riley Greene, belong to Marvel / Disney. Anything depicting realistic people, places, etc are purely coincidence, as this is all fictional. Also, I’ve never been to Crystal Lake, Illinois; I just googled as much as I could, so my apologies if things are incorrect or inaccurate.

Prologue - First Contact

Sound --
1- Sound is a periodic disturbance of the medium (air, ground, water, etc) that radiates outward in straight lines in the form of a pressure wave. The effect these waves produce upon the ear is perceived as sound.
2- Sounds are vibrations that create disturbances in the atmosphere in the form of pressure waves. These pressure waves are perceived by our ears as sound.

***********

Universe 7133
April 10, 2009 (3 years prior to the Battle of New York)
Planet C-53: Earth
SHIELD base: Polestar
Location: Classified

 

A dull headache had begun to form under the cold metal and humming fluorescents of the SHIELD facility. He’d already shifted the position of his legs seven times, and Fury’s usual limit was nine before he got officially annoyed. Goose’s blue cat bed sat empty in the corner like an omen—  if the orange tabby wasn’t napping in Fury’s office, it meant that she was wandering the building somewhere. Never a good sign. 

 

Agent Phil Coulson loved his job— really, he did, wouldn’t change it for the world— but after the day he’d had, he was more than ready to head home, pour himself a healthy glass of Chianti, and spend some up close and personal time with Lola. (May and Hill were always saying that the cherry-red 1962 Chevrolet Corvette was the only consistent woman in his life. He was starting to think they had a point.) But instead, here he sat, waiting for Director Fury to finish eyeballing the report on yesterday’s Taipei mission.

 

Any evening plans were suddenly tossed out the window at the sound of the Director’s phone ringing, the man in question snatching it up with a clipped, “Fury”. 

 

His superior listened for a good thirty seconds before raising an eyebrow. “Got it.” Hanging up, he fixed his famous gaze on Phil, the one that never failed to send most agents scrambling. 

 

“New potential Enhanced for the Gifted Index. Grab a team and go check it out. ”

 

Sorry Lola. 

 

“Yes, Sir.” 

 

Hastily exiting Director Fury’s office, Phil whipped out his phone and shot Barton a text about the mission, then went to grab some things from a nearby equipment room. It wasn’t until a few minutes later (and was that a yelp he just heard in the distance?) that he received a ‘K’ in response. 

 

Heading down to Tactical, his footsteps echoing sharply in the empty hallway, Phil jumped slightly at the sudden appearance of Goose slinking his way, seemingly headed back to Director Fury’s office. He had no idea how a cat could possibly look so thoroughly pleased with itself, but somehow, this one did. Phil just gave the feline a wide berth as she trotted by, hoping that whatever Goose did this time wouldn’t lead to a new stack of paperwork on his desk when he returned. 

 

Phil was entering the aircraft hangar when Clint strode up beside him, the archer sporting a few angry red scratches down his arm. 

 

He raised an eyebrow at the agent. “Let me guess— Goose find you in the vents again?”

 

Clint adjusted his quiver straps, a muscle twitching in his neck. “She’s like a freaking bloodhound! I’m telling you, Coulson, that cat has something against me.” 

 

The real question was whether Goose was doing it of her own accord, or if Fury had somehow trained the cat to keep Clint out of the vents (or even simply for his own amusement). 

 

A fully prepped tactical team was already waiting for them at the Quinjet. Phil slipped on his favorite aviator sunglasses and pulled up the digital mission file on his phone. 

 

“Alright, load up everyone,” he ordered after giving the information a quick scan. “We’re headed to Crystal Lake, Illinois.”

 

***********

 

Phil spent the two-hour flight to Crystal Lake reviewing the information they had (what little there was) — SHIELD systems had apparently flagged a call from the town hospital to the local police, picking up on certain keywords and such that indicated an ‘unnatural’ event. 

 

He played and replayed the call recording about six times, picking apart every detail possible— a hospital desk clerk (female, older sounding, likely over forty) explaining in a panicked, jumbled mess that a patient had somehow just ‘ blasted Dr. Weaver through a wall ’ and that they ‘ need to send the damn army or something! ’. The police responder eventually managed to calm the woman a bit and get a better explanation (but only after assuring that multiple squad cars were en route). 

 

It just happened out of nowhere. ” Phil had to strain to make out her voice among the hectic commotion in the background, the hospital seemingly in chaos. “ One second, everything’s normal, Tammy’s doing some afternoon rounds. An alert went off, Tammy paged for Doctor Weaver, apparently the coma girl finally woke up. Then I heard some shouting, next thing I know there’s a big boom, like an explosion. I ran around the corner and found Tammy and Doctor Weaver laying in a pile of dry-wall! I think Tammy’s arm is broken!

 

Using the rest of the recording, as well as a few calls between local police officers about the situation, Phil managed to deduce the following: 

1-The potential Enhanced is a teenage girl; 

2-She’s spent the last two weeks in a coma, having been injured in some recent local accident; 

3-Upon waking up, she somehow sent two grown adults through a wall; 

4-The potential Enhanced immediately fled the scene, and in the chaos managed to escape the hospital and disappear into the nearby forest park, where police were currently searching for her. 

 

It was probably just another case of accidental super-strength, likely temporary, and they’d just contain her until it wore off or put her on the Index. Fury likely hoped that they finally found a legitimate case of telekinetic abilities (all the ones so far were either fakes or just hadn’t panned out) but Phil honestly doubted it. 



It was early evening in Crystal Lake by the time the Quinjet landed in a small airfield outside of town, where three black rental SUVs awaited to ferry them to their destination. 

 

Crystal Lake, Illinois was the epitome of quaint northern suburbia — crisp, neat, and all with a certain blandness to it. It reminded him a lot of his childhood actually — same kinds of orange and tan houses, same smell of crisp evergreen in the air, even the same soft sepia tone that sometimes bathed the land. He couldn’t decide if the familiarity was comforting or unsettling, as both seemed to be stirring in his chest. Phil hadn’t been back to his hometown in over a decade at this point, not since his mothers’ passing. Strange to think it was only an hour north of here. 

 

When the SHIELD team finally rolled into the parking lot of Crystal Lake Forest Park, there were already four police cars sitting at the woods entrance, lights flashing blue and red onto the wall of trees. Phil immediately dispatched a handful of agents to handle things at the hospital next door before addressing the issue of local law enforcement. 

 

Phil approached the standby policemen, straightening his tie as he walked. “Hello,” he offered his token mild-mannered smile. “Can I ask who’s in charge here?”

 

One of the older looking cops, standard bulky frame and square jaw, came forward and shook his hand. “That would be me. I’m Chief Thomas. You are?”

 

Phil whipped out his badge. “Agent Phil Coulson with the Strategic Homeland Intervention, Enforcement and Logistics Division. We’ll be taking over the scene from here.”

 

Chief Thomas frowned. “What for?” 

 

“I’m afraid that’s classified.”

 

The cop sighed, hands coming to rest on each side of his hip. “Always is with your lot. Well,” he looked back at the extensive forest behind him, “I’ve already got a few men in the woods searching for her.”

 

“You can go ahead and radio them to pull out.” Phil smiled more genuinely now, immensely relieved that it hadn’t turned into the macho territorial pissing contest it often did with small-time sheriffs. “And not to engage if they spot her on their way back.”

 

Phil walked back over to Clint as Chief Thomas radioed his men.

 

“So,” he addressed the archer, who was leaning leisurely against the black SUV as if it was the most natural place in the world for him to be. For a split second, Phil saw the scrappy, bitter teenager he’d found at the circus all those years ago. But it was gone with a blink. “How do we want to do this?”

 

Phil had done ‘Potential Asset Assessment’ plenty of times, and if he wanted, he could easily stomp around and bark out orders and demands of how to bring the girl in according to protocol. But that wasn’t the kind of agent Phil was; he valued his peoples’ opinions, especially Clint’s, as the archer was known for his ability to look at the whole picture and assess variables that others might not have considered. 

 

“Well, we’re going in pretty blind.” Clint pushed himself off the vehicle. “Safe bet to say the girl is scared, injured, confused, running on adrenaline and morphine.” He grimaced. “We could send in a full tactical team like usual, but given her age that might not be the best approach, and with the potential of unknown powers we want to keep her as calm as possible. I say two-man team, you and me. One below to make contact and one above for cover in case things go south, with the rest here as backup if needed.”

 

“Agreed.” It didn’t need saying who would do which. Phil informed the other agents of the plan, telling them to hang back and be ready in case they called for backup. 

 

When Phil and Clint entered the forest, Clint— using a grappling-hook arrow— immediately made his way into the thick evergreen canopy, as Phil advanced upon the main walking trail. 

 

The sun had fallen below the treetops, bathing Phil in the faded hues of dusk and stretching the shadows around him. The hum of nocturnal critters waking for the night grew as he crept through the dense woods, following the foot-worn path in the ground, his hand hovering near his gun on trained instinct. The forest around him seemed to breathe, like a great beast watching its prey, and every twig snap and leaf rustle had his trigger finger twitching. Only the knowledge that Clint was watching over from above kept his unease at bay. 

 

For almost twenty long minutes, Phil simply advanced deeper into the bowels of the forest, high on alert yet finding nothing. But then, something new reached his awareness— an odd noise, not unlike that of a dying animal. It quickly became a howling keen that sent goosebumps down his spine and curdled his insides. 

 

Fighting some inexplicable instinct to avoid it, he followed the unsettling sound until he finally found what he’d been searching for. 

 

The potential-Asset was curled up in the dirt against a massive oak tree, bearing a hospital gown and wrapped seemingly head-to-toe in bandages. She was clearly crying, her face hidden behind her knees as she wept like a creature possessed, her sobs swallowing the natural cacophony of the woodland evening. Her anguish was so raw and ugly and palpable that it made Phil’s chest hollow with ache, because there was no mistaking the sound of grief. He’d been in this job too long to not be uncomfortably familiar with the sight of someone having just received the worst news imaginable. 

 

Pushing those thoughts away, Phil crept towards her as quietly as his stealth training would allow, but a mere second later her head snapped up to look at him, eyes blown wide with fear. He froze, but his alarm turned to confusion when the girl immediately slapped her hands over her mouth with an audible smack

 

Subtly adjusting his jacket to ensure that it covered his gun, he decided to go ahead and step out into the open, hands held out in front of him to display peace.

 

“Hi there, my name is Phil.”

 

She didn’t respond. Her bandaged hands remained tightly sealed over her mouth, her eyes shining with terror, choking on barely restrained sobs. 

 

“I promise, I’m not here to hurt you.” Phil slowly walked closer, praying to God that she wouldn’t freak out, that today wasn’t the day he’d get obliterated by some weird uncontrollable nonsense like lava hands or acid breath. “I heard you need some help.” 

 

As he continued to approach, the girl panicked and hastily began backing into the tree, flattening her body against it like it might send her to Asgard if she tried hard enough. Phil immediately halted in place, not wanting to scare her more or make the situation any worse. 

 

The fading sunset now bled through the forest, allowing Phil to see that the skin peeking out from beneath her bandages was gruesomely red and raw, like flayed meat on a skillet, so bad that it actually made his stomach turn despite it being far from his first time with this kind of thing. No, he’d seen wounds like this before on agents injured in fires or explosions. The damage was so extensive that he couldn’t make out any of her identifying features, and even most of her hair had been burnt away. Covered in bandages and burns, she honestly looked like some half-baked Freddy Krueger, and Phil could only hope that their scientists’ advanced medical tech would be able to heal her. With just a hospital gown to cover her in the late April evening and likely going into shock, the girl was now shivering violently. 

 

Not moving from where he stood, Phil slipped his jacket off and held it out to her, making sure to angle his body so she wouldn’t see his gun. The girl just stared, silent as a statue except for the sobs that still hiccuped dryly from her throat, but then her eyes darted up towards the treetops. Phil followed her sightline but couldn't spot anything unusual — until he caught the barest hint of movement. Squinting, he was just able to make out a shadowy figure among the branches— Clint.

 

Now Clint Barton was an agent of SHIELD, trained by Fury and Phil himself, a natural expert in stealth and a world-class spy. There was no way anyone without years of experience should have been able to spot him, let alone some random teenage girl. 

 

But there was no doubt— she was staring right at him. 

 

Perhaps she had some kind of clairvoyance? Or maybe heightened senses? Either way, Phil hadn’t counted on her spotting his backup, so he had to figure out a way to work this, and fast. He quickly called to mind the SHIELD tactics for handling adolescents in trauma situations.

 

“That’s my friend, Clint. He won’t hurt you, he’s just watching over us, keeping us safe.” Phil turned back to her. “Clint’s always liked high places; even got nicknamed ‘the Hawk’.” He gave her a conspiratorial grin. “But sometimes when he’s not around, I call him Tweety Bird.”

 

“I heard that.” Clint’s voice crackled in his ear through the comms. The girl’s eyes flickered to Phil for a second before returning to Clint’s hiding spot. 

 

Phil realized that he wasn’t going to get anywhere with her like this, so he pressed his earpiece. “Hey Tweety, come down and say hi to our new friend here.” 

 

“Sir, you sure about that?”

 

“Positive,”  Phil assured, smiling lightly at the girl. Something in his gut said this was the right move. 

 

There was no response, but less than a minute later Phil felt Clint slink up behind him. To Phil’s relief, the girl actually seemed somewhat less tense now that ‘the Hawk’ wasn’t looming from above. 

 

Phil offered her his jacket again. “Would it be okay if I come over and give this to you? It’s getting pretty cold out here.”

 

For a long moment, nothing. Then— a tiny nod.

 

Phil cautiously walked over and handed it to her, but she didn’t reach for it — either to keep her hands over her mouth or because she was in too much pain to move. So he got a little closer and draped it around her instead. Feeling victorious when she didn’t try to distance herself from him again, Phil crouched down to meet her at eye level. The girl leaned away, and Phil finally got a good look at the hospital bracelet on her wrist, which read ‘Greene, Riley A. ’. 

 

“Riley Greene.” Phil motioned to her bracelet tag at the girl’s startled look. “That’s a pretty name.” 

 

The air around them sat heavy with tension and the chirping of early nightfall, which settled on their skin like a whisper. The three were breathtakingly still, each of them afraid to shatter this delicate moment of uncertainty. Phil took a breath, trying to choose the best way to go about this.

 

“Riley,” he finally said, breaking the silence. “Do you remember learning about Captain America in school?”

 

The girl’s brows knitted together at the sudden change of topic but she nodded anyway. 

 

“Well I’ve always looked up to Captain America. Ever since I was a kid, I wanted to be just like him. So when I grew up,” he slipped his badge out, showing it to her. “I joined an organization called SHIELD, so that I could help people like he did.” He tucked his badge away and took another breath, eyes set with earnesty. “Will you let me help you, Riley?”

 

Nothing. She didn’t move, didn't make a sound. 

 

With every second that passed, anxiety crawled into his skin and coiled into his shoulders. If she refused—told them no or tried to run—they’d have to bring her in by force. And while they’d brought in potential assets by force many times before, one this young would no doubt weigh on his conscience quite a bit more than usual.

 

But finally, she nodded. 

 

Phil released a breath he hadn't realized he was holding. “Good. I’m really glad to hear that.” He gave her a reassuring smile, shifting in place. “So, for everyone’s safety, we need to get you away from here for now. If it’s okay with you, Riley, we’d like to take you back to a SHIELD facility so we can treat your injuries and then figure out what’s going on.”

 

Another pause. Then another nod. 

 

“Can Clint come over here and pick you up? He’s going to carry you back to the car so that you don't aggravate your wounds.” Even in the dim light, Phil could see the bandages all over her body turning dark as blood and pus seeped through. Phil figured the only way she’d made it this far with her injuries was a combination of adrenaline, shock and the morphine in her system. But now that all of that was starting to fade, he doubted she could even stand right now if she tried.

 

Riley gave a hesitant nod. The expert archer walked over and crouched down, gently wrapping his muscular arms around her tiny wounded frame.  

 

“Up we go.” Clint said as he hoisted her off the ground with ease. The girl still kept her hands tightly sealed over her mouth as they followed the path out of the woods, looking impossibly small and fragile in Clint’s arms. Phil radioed the squad to inform them that they were returning with the asset. Mission accomplished. 

 

The girl had slipped into unconsciousness by the time they reached the cars, whether it be from her injuries or pure exhaustion, Phil couldn’t say. The sight stirred up a wave of melancholy, because he knew this young girl’s life would never be the same again. And by the tense set of Clint’s jaw, Phil could tell he was likely thinking the same thing. 

 

Phil gazed up at the night sky, a sea of scattered stars bearing down on him, and allowed himself a moment to wish for a world that was better. Simpler. Where these kinds of things didn’t happen. Especially not to someone so young, so undeserving.

 

But then he forced himself back down to reality, and shut the car door behind him. 

 

***********

3 years later… 

May 2, 2012 

 

Phil Coulson ran a hand through his fading hairline, stress tightening into a knot at the base of his neck. 

 

Not only did Loki get away with the Tesseract, he'd also somehow taken Dr. Selvig and a handful of agents, including Clint. 

 

This was a mess— a huge, Level Seven mess.

 

Director Fury emerged from the Sat-Com room and stalked down the hall. Phil fell in line next to him. “How did it go with the World Security Council?” 

 

“I convinced them that a response team is necessary.” They entered the Director’s office. Fury strode over to the holo-screen and pulled up a file labeled ‘Avengers Initiative’. He stared at the information for a few minutes in silence before finally turning to Phil. “Status?” 

 

“Still no word on Loki or the cube. Agent Romanoff is en route to Banner. I leave in an hour to talk to Stark.”

 

Fury swiped through various screens, looking over some data. “Any sign of Thor?” 

 

“Not yet.”

 

Fury frowned. “I’m not liking our chances here, Coulson.” 

 

“Things don't look good, Sir,” the agent agreed solemnly.

 

Fury grunted in annoyance. “I guess it’s time to pull out all the stops.” He pressed a few buttons and pulled up a new file from the ‘Potential Assets’ folder.

 

Phil’s stomach dropped into the floor. “Sir?”

 

“I know our plan was to wait, but the situation has changed.” Fury moved the file into the ‘Avengers Initiative’ folder.

 

“But sir, she’s only eighteen-”

 

“-which is legally old enough to join the military.” Fury cut him off. “Bring her in.”

 

For the first time in probably his entire life, Phil hesitated to obey a direct order from Nick Fury. “Sir, I don't know…”

 

“We won't force her if she doesn't want to.” 

 

“You and I both know she’ll want to.”

 

Fury made a noise that could have been mistaken for a sigh. “I don't like it either, Coulson, but with what’s at stake here, we can’t afford not to.”

 

Phil swallowed hard, fighting the lump in his throat. It was one thing to recruit Stark and Banner, but her ? While Phil certainly couldn’t deny that he’d been reluctant when Fury had first assigned him as her handler, they’d grown quite close over the past three years.

 

“Is this going to be a problem, Agent Coulson?” Fury’s tone was thick, stern, a clear sign that he was not pleased with Phil’s hesitance. “Do I need to assign her to someone else?”

 

“No, Sir.” Phil swallowed and straightened his posture, forcing any emotion from his face. “Consider it done.”