Hey there! ^^ This is my first story on fan fiction. It was supposed to just be a one-shot, however I got a bit carried away and I'm hoping on extending it to a few chapters. Feel free to review, I know I'm not the best writer. I hope I can continue this, but I will be a bit busy for a while, so I'm hoping to write a lot over Christmas break.

Anyway, I hope you guys enjoy~

PS: This story will be packed with Cas!whump. Also, if you are offended by allergies (specifically peanut) please don't read this.

It hurt like a bitch when he fell. Or, at least, that's how Dean would say it. Although it had been over two months since Castiel's feet hit the ground, he continued to be overwhelmed by the invisible rules and customs of being human. He had always been fascinated by the complex race, but over the course of the many weeks he spent trying to find some balance, he gained a sense of appreciation for wingless beings as well.

There were just so many unwritten laws that he couldn't grasp. So many rules that humans had to remember, it made his head spin just thinking about it. You can't say this, you must do this instead, or don't forget to do this at this certain time. Eat. Drink. Get six hours of sleep every night. Or…perhaps it was eight..? Castiel didn't remember. In fact, he didn't remember most of the rules, which often resulted in a session of mocking from the Winchesters. It was all profoundly embarrassing, but Castiel eventually became somewhat used to it. After all, it would take time before he could be comfortably adjusted into human society.

However, the most difficult part of being human for him, was remembering to eat at least three meals a day, and additional snacks in between. He had gotten accustomed to drinking water rather quickly, seeing as though the human body was made up of approximately 60 percent water, so he would have been dead by now if he hadn't undertook that habit. Strangely enough, he found out that he was quite picky with his food.

Castiel hadn't 'grabbed a bite to eat', as Dean would put it, since breakfast. He could already feel it's toll upon his body. They were supposed to eat over an hour ago, but Sam, for some reason, was still out, and Dean had been deeply involved in something on television, so Cas was left alone with a grumbling stomach and no food.

The familiar pang of emptiness in his stomach reminded him of how exactly hungry he was. Castiel glanced up from his hands, clasped together over the table to meet the olive green eyes of the eldest Winchester.

"Dean."

"Yeah, Cas?" Dean's eyes flicked up from the newspaper in his hand, searching for another job. Castiel shifted slightly, uncomfortable with the question that filled his mind.

"Can we…" he paused to clear his throat. "Uh..can we grab a bite to eat?" Dean set down the newspaper and chuckled slightly. Castiel couldn't stop the blush from spreading across his cheeks.

"You hungry?" The blonde stood up from his chair and stretched out his arms languidly, contemplating food options. "Well, Sammy forgot to go to the grocery store again, so bad timing." He flashed a sarcastic smile and reached for the car keys in his jacket pocket.

"We are going to the grocery store?" The former angel more concluded than asked, as he stood up from his chair. Dean nodded as he headed for the door.

"Yeah, why not? I need me some pie anyway." He grinned in anticipation as he headed out the door. Castiel merely raised an eyebrow. Humans…they never ceased to fascinate him. It was always interesting how one could love a food item so much.

Castiel followed the Winchester out the door of the dingy motel room and climbed into the passengers side of the car. This happened to be a rare occasion as the front seat was Sam's favorite place to sit, leaving Castiel to sit by himself in the back. However, Sam was off all decked out in FBI garb in order to interrogate a possible 'job' that they had been reading up on earlier. Now, it was just Dean and Cas.

—

"Ah, finally, some good food for a change," Dean mumbled to himself as they entered the grocery store. From what Castiel could see, there was mostly processed items and several things he couldn't even identify as edible, however he was too hungry to care at the moment.

"Here," Dean said as he handed the brunette a basket. Castiel had been to enough grocery stores on his own to understand that you collect the food products in the baskets, and then bring them up to the front desk to pay for them. He had learned the hard way, that you cannot eat the food without paying for it…

As Dean left to go look at a large selection of pastries, Castiel observed the condiments isle. There were many things there that he had never even heard of, like mayonnaise, relish, and peanut…butter? The brunette squinted at the jar of what seemed to be a creamy, brownish substance as if he had read it wrong. From what he understood, a peanut and butter were two very different things…how could humans find peanuts and butter combined to be enjoyable?

Castiel studied the ingredient further, and eventually decided to add it into the basket. In order to adjust to society more, he would have to try new things. Perhaps he would like the peanut butter? If humans liked it, then he would surely have to give it a try.

Walking further down the isle, Castiel grabbed a loaf of bread to make a sandwich and tossed an additional bag of potato chips, along with a jar of some jelly substance that had the same brand name as the peanut butter. He had heard of jelly before, that it was sweet and tasted like fruit. Perhaps it would mix well with the peanut butter.

Shopping for food was more time consuming than he thought.

A few seconds later, Dean appeared at the end of the isle with grocery items stacked up to the brim of his basket. Many of the items, he noted, were slices of various types of pie. He would surely get sick if he ate all of those slices in one sitting, so the ex-angel proposed that he keep a close eye on the pies and make sure that they were not disappearing too quickly.

"Alright, I'm done. How bout you?" he asked, before his eyes trailed down to the other's nearly empt basket.

"Seriously, that's it?" Castiel looked down at his food choices with a frown.

"Is this not enough?" he asked, confused. Dean shrugged, and lazily tossed a few things from the shelf into the brunette's basket as he made his way to the register.

"Just don't want ya to get hungry later. Besides we gotta get stuff for Sammy." Dean remarked as Castiel followed him up to the front of the store. The blonde placed both the baskets on the counter and fumbled for his wallet while the employee began scanning the items.

"You know.." The blonde trailed off as if reviewing his thoughts.

"Know what?" Castiel knitted his brows together in confusion.

"Just sayin'..but you oughta eat more, Cas." Dean said, giving a sideways glance towards the other as he handed the money to the cashier. He couldn't help but worry about him at times. Especially since he had fallen. Castiel barely knew a thing about the human world, let alone surviving in it. Screw it, if it made him sound like an over protective mother. Dean didn't care. He had never seen the other so vulnerable and so…human before, and to say the least it frightened him. The angel of the Lord, now a mere man struggling to survive in a cruel world…it was painfully ironic.

Castiel cocked his head sideways, something he always did when he was either trying to understand something or was trying to read the mood. Both of which he was terrible at.

"Why do you say that..?" There was a long pause before Dean sighed heavily, looking over at the brunette.

"Nothing, never mind." He quietly thanked the cashier as he took the bagged food and headed out of the sliding doors, leaving Castiel to contemplate what had just happened. From what he could recall, he ate the required amounts of food a day. Sure, the average human male might eat more than him, but it wasn't like he needed it. He could function just fine without eating for a few days if need be. Then again…the last time that happened, the end results weren't pretty.

But that was besides the point.

Castiel followed the other out the door, scratching at something in his nose as he slumped into the car next to Dean, letting loose a large sigh. He was about to ask why the other had told him to eat more in the first place, but was interrupted when it felt like something was crawling up his nasal cavity. Cas wrinkled his nose, felt a slight spell of panic wash over him at the foreign feeling, however he kept his mouth shut in order to save from causing any trouble with the other.

"Here," Dean glanced in his direction as he held out a bottle of water. "You look like you need it."

Castiel took it silently and immediately opened the cap and drank about half the bottle in a few gulps. He sighed, and bit his lip. He was inexperienced in the interactive world, but if the brunette knew anything about conversation, he could tell that this would be called an 'awkward silence'. The former angel looked down, wrinkling his nose again. The strange feeling came back again, and he had no idea what to make of it.

He was familiar with the term of 'sneezing' that began with an itching sensation in the nose. It was the act of expelling unwanted foreign substances from the body, so why wasn't he sneezing? Castiel rubbed his nose in annoyance, earning a strange look from the drivers side.

"You good, man?" Dean cautiously examined the other as if he were afraid he was about to fall apart.

Damn, this was quite aggravating.

"Fine.." Cas mumbled, wiping the sleep of his trench coat across his face where a slimy liquid had apparently dripped out of his nose. This couldn't be normal for a human…

"Uh..Dean," He swallowed with a bit more effort than usual. "Is…is this normal..?" Castiel looked to the other for an answer while holding up the sleeve to his trench coat, with a feeling of panic pooling in his stomach. What he received, however, was nothing less than exactly what he suspected.

"Yeah, you're fine. I bet you're just comin' down with a cold." Dean chuckled lightly as he revved the engine alive and drove out of the parking lot. He felt the tiniest bit guilty about it, but seeing Castiel so worked up about the smallest of natural human reactions amused him. It wasn't some sort of sadistic trait, god no, he felt awful for the guy. For christ's sake, he fell from the goddamn sky. His body was probably still trying to compensate for suddenly adjusting to the human world. In fact, Dean was surprised that he hadn't caught some sort of sickness earlier.

However he couldn't help but chuckle sometimes when he saw Castiel overreacting to the simplest of things.

The two of them eventually arrived back at the motel, stomachs rumbling so loud Dean was surprised the no one had given them strange looks. He tossed the bags of food onto the counter as soon as they reached the room and clasped his hands together.

"Alright, finally! Time to eat!" Castiel immediately reached for the peanut butter and the bread. As if on cue, the door opened with a solemn looking Winchester on the other side of it.

"Hey," came a tired voice. Dean looked over at his younger counterpart and gestured to the food.

"Hey. Got some grub, and before you ask I got you your girly little salad this time." Sam rolled his eyes and dropped his pack on the floor beside the table.

"Anyway, case is a bust. The woman who we suspected was a demon, just turned out to be a complete lunatic," Sam sighed exasperatedly and pulled out a chair. Dean made a disgusted noise and tossed his brother a pre-made salad he had carefully chosen from the store.

"Here, eat up. You too Cas," Sam nodded as a thanks, tearing open the sides of the plastic container before grabbing a fork from the drawer. Castiel tried to ignore the look Dean gave him, and observed as the brothers began ravishing the food. It was especially human males, he found to be aggressively hungry, to put it in the least.

Castiel grabbed the jar of peanut butter and unscrewed the cap. It smelled quite nice, salty, but with a hint of sweetness. Almost immediately he felt the tingling, itching sensation in his nose again, only this time it was stronger. He sniffed and rubbed his nose. This was definitely a strange cold…maybe certain things aggravated it more?

After he spread a copious amount of peanut butter and some of the strawberry jelly each onto a slice of bread, he licked his lips before hesitantly sinking his teeth into the first bite.

…..

…

Amazing, was the first thought that came to his mind.

With the saltiness of the peanut butter and the savory sweetness of the jelly combined, Castiel dared say it was one of the best things he had ever tasted. Ignoring the tingling sensation in his nose, and now his mouth, he dove in for another bite. He caught Dean's eye, who gestured at the sandwich with a mouth full of food.

"Good right?" The brunette nodded in agreement and took another bite. But this time he felt a little strange. Castiel slowly closed his mouth and felt his bottom lip, brows knitted in confusion and slight anxiety. The tingling sensation turned into more of a burning one, causing him to gag slightly on the chewed up food. Unfortunately, that only earned him an utterly bewildered expression from both of the brothers.

Castiel gripped the edge of the table in haste. The sensation was much stronger than it had been in the car. This time he truly was panicking. What he was experiencing could not be a mere cold, because no sickness could be brought on this quickly. None that he knew of, at least.

Castiel reached for his throat on reflex, clawing at it in effort to get rid of the pressure that was beginning to build up. Either his throat was physically swelling up so much he could feel it from the outside, or he was about to let loose the biggest goddamn sneeze ever. Unfortunately for him, the first possibility seemed to be the most likely.

"Woah, Cas! What the hell?" The piece of pie on Dean's fork slowly slipped off as he and Sam exchanged nervous glances.

The fingers on the brunette's hands mercilessly clawed at his throat until it turned an unnatural shade of red. It felt as though someone was slowly suffocating him with their hands continuously wrapping around his neck. Castiel suddenly wheezed and nearly fell out of his chair as the world took a spin.

"Damn it!" Dean scrambled out of his seat and caught the other just in time. "Sammy, what's happening—is this—?"

"Shit." Sam left to retrieve the med-kit from his pack without a word, but they both knew what the other was thinking.

An allergic reaction to peanuts.

Who knew that out of everything, Cas would be allergic to peanuts? Out of every single damn dangerous allergy the fallen angel could have had, it had to be the number one most common. One of the most life-threatening allergies that anyone could have.

Oh god…oh god.. They needed to get to the hospital.

"Sammy!" The blonde exclaimed as he supported a wheezing Castiel.

"Dean, I can't find an epi-pen, we've got nothing." The youngest Winchester looked over, eyes filled with terror for their friend. He couldn't bring himself to look at the former angel. It was too hard to see him so weak and suffering, when the Winchesters had known him to be so strong and infallible. But now, he was just as human as they were.

Sam could hear the strangled gasps and wheezes for air from the other, and sprung to action.

"Dean, we have to leave now. We've gotta get him to the hospital." Dean nodded and slung one of the brunette's arms over his shoulder, panic pooling in the pit of his stomach. Sam took the other arm and hoisted Cas up, the two of them guiding him out the door as he coughed helplessly. Out of the corner of his eye, Dean could see bright red rashes forming around the others mouth, throat, and around his collarbone, making him grimace.

Castiel lurched forward with a gag, making them lose their balance, and nearly fell out of their arms. His legs gave out underneath him, as an anaphylactic reaction fully took over his body. He shuddered and blinked out tears from his eyes, face and throat burning from the intense allergic reaction he was experiencing. Castiel couldn't handle it. He could feel the walls of his throat closing in on him and he was already becoming lightheaded.

The thought of losing their friend to this disturbed both of them. Same and Dean rushed out to the car and laid Castiel across the back seats. They were the goddamn Winchesters. No one was dying on their watch today.