Day One
Dean Winchester woke up to the sound of the alarm clock playing Kashmir by Led Zeppelin, and he rubbed sleepily at his eyes. The song continued to play as the slightest hint of a frown crossed over his lips. Normally, Sam was not only up before him, but was showered, dressed, with coffee in hand. Yet that morning there was no sign of his little brother. His eyes turned to the bed and Dean froze.
There sitting on the bed in which Sam had fallen asleep in last night was a fish bowl with a tiny creature inside it, the creature couldn't be larger than his palm, and it was staring right at him. Dean slowly moved over to the fish bowl and picked up in his hands, his eyes going almost completely wide. There inside the little fish boy with the lower half of his body a red tail with pinkish fins, staring out at him with big scared eyes, little webbed hands pressed to the glass, was Sam with red and pink fins poking out from beneath his hair where his ears should have been. The fearful tears that slipped from his eyes looked like bubbles. "Sam…?"
The little merman Sam looked at him mouthing his brother's name and swimming up to the top of the bowl trying to get his arms around the rim of it. "Dean!" he said though his voice was very small, sounding like it had when he was a little kid. He looked scared and he held up his tiny hand towards Dean. "Dean!"
Dean held out his hand and gave Sam his little finger to hold. "It's…it'll be alright Sammy. We'll figure this out," Dean said though his mind was racing trying desperately to figure out how the hell this could have happened. As he watched Sam slipped back down into the bowl, sitting with his tail tucked beneath him on the blue colored stones that lined the bottom of the bowl. Dean sat on the edge of the bed, fish bowl in his hands, looking at his little brother the baby merman.
Sam was watching him with those big sad eyes and Dean carefully put his finger into the bowl. Sam swam up and wrapped his arms around Dean's finger practically clinging to him. He was hungry, very hungry, but the fear that he was feeling overwhelmed that. The little merman looked up into his brother's face and gave him the smallest of smile and he held onto Dean's finger tightly as Dean pulled his hand up out of the water and caught Sam in his palm.
God, he's so small, Dean thought and smiled down at Sam. "Damn it Sammy you're so tiny what am I going to do with you?" he asked only to have Sam blink up at him with a confused look. Carefully, Dean put Sam back in the bowl, watching as his little brother started to swim around happily. As he thought, Dean realized that he was going to need things for Sam to eat things that weren't fish food. Probably would like that, fish food wouldn't be that tasty I bet, Dean thought and carefully set the bowl on the side table. "Sammy I'm going to run to the store quickly. I'll be right back." Sam looked at Dean with the most pathetic of gazes that made Dean want to stay right put, but he had to go out and get things that Sam might need.
It nearly broke Dean's heart, the look that Sam gave him as he walked out of the room, making sure the blinds on the windows were closed, and one light was on just so it wouldn't be too dark for the little merman, and that the door was locked. There was no way that Dean wanted anyone to wander into the room and see Sam like that, in Dean's mind if that happened Sam would be taken away and he would never see his little brother again. He got into the Impala and started the car, deciding that he should head to the grocery store first.
The looks he received from the women inside the store once he had parked the car were driving him completely insane. Especially with what he was looking at, more or less it was baby food. He could hear them giggling at him as he looked at it, settling on getting some canned fruits, which seemed like the best option that he had. Peaches, pears, and orange slices, but just as he was leaving he spotted some bath toys for babies and Dean smiled slightly. He picked out a rubber duck and a small ball that would float in the water before he paid for the items, and went back to the Impala.
His eyes fell on the clock in the Impala and he silently cursed under his breath, he had been gone longer than he had wanted to leave Sam alone. There was a moment where he contemplated speeding just to get back to the motel as quickly as possible, but he decided against it; knowing his luck he would just get in trouble with the police and sent to jail, it wasn't like he was an upstanding citizen. Dean knew that at some point he might…have to go to a pet store to get some things to safely clean the bowl that Sam was in but for now, he just wanted to get back to his brother.
Dean pulled into the parking lot of the motel, and parked, grabbing the bag from the passenger seat before he got out of the Impala and locked it. He moved faster than normal as he got to the motel room door, fumbling with the key as he unlocked it and went inside. His eyes instantly went to the fish bowl and a small smile formed on his face. Sam was swimming near the top of the fish bowl around and around in a circle, his hair swept back off his face as he swam. When Sam spotted Dean, the little merman stopped his swimming and went over to the side of the bowl, hands pressed against it, his eyes seeming to glow with happiness.
"Hey there Sammy, I'm sorry I was gone so long," Dean said as he sat on the edge of the bed and pulled one can of each of the different canned fruits he had gotten out of the bag. "Okay so I got you this. Point to which one you want to try." Sam, who seemed to understand, pointed to the oranges first and Dean opened the can, making sure to get a small enough piece that Sam could eat. He held it just over the water and Sam swam up, taking the bit of fruit in his hands and biting it.
Sam made a face and held it back up to Dean. "No likey," he said with a small pout, which only made him seem even cuter. Sam pointed to the peaches and once again Dean opened the can and gave Sam a small piece for him to try. With one bite Sam's entire face lit up and he swam around in a happy circle, nibbling on the piece of peach. "Yummy!"

Day Three
Sam's fish bowl needed cleaning, which meant that Sammy was once again back in the bath tub while Dean carefully cleaned all the scum out of the bowl. Hell, Dean probably wouldn't have noticed if he didn't wake up to find Sam wiping the side of the bowl with a piece of cloth he had gotten from one of Dean's old shirts for a blanket the other day. Currently Sam was swimming around in the bathtub chasing after the ball that he just could not seem to get a hold of.
Every time Dean heard the sound of splashing, it made relax just a bit if only because it meant that Sam wasn't floating dead. He glanced over at his little brother and reached into the tub, scooping him out of the tub, earning a squeak from the little merman. "Bath time for you Sammy." Sam shook his head over and over again and Dean just chuckled softly. "You need it kid." Sam struggled in Dean's hand as Dean very carefully washed him in the sink, using a washcloth to gently clean his little brother. Once Sam was clean Dean set him on the edge of the sink as he proceeded to get the tank set back up.
It was a matter of minutes before Sam was happily swimming around his tank again, and there was a smile on Dean's lips as he set the tank on the floor of the bathroom, and moved back into the main part of the motel room, leaving Sam there for the time being. He grabbed up his cell phone and punched in Bobby's number. It rang a couple of times and Dean was starting to wonder if the other hunter would actually pick up his phone. "Damn it Bobby answer your damn phone," Dean cursed under his breath in the process of opening up some more cans of peaches for Sammy's food.
As Dean had started to cut them into more bite-sized pieces, Bobby answered the phone. "Dean? Didn't think I'd hear from ya so soon. What do you need?"
Dean set down the knife he had been using and sat down on the edge of the bed, balancing the phone between his shoulder and his ear. "Well, kinda ran into a slight problem and won't be able to do the job we were sent on Bobby."
"What did you idjits do this time?"
"What? No Bobby we didn't do anything!" The manner in which Dean said that was extremely defensive, though he could honestly see why Bobby would assume that they had done something wrong. With their track record, they did call often when they needed Bobby's help…or had done something stupid. "Bobby something happened and Sam's a baby merman now." There was silence from the other end of the line. "Bobby?"
"You're joking right?" Bobby asked him, clearly not believing a word that Dean said about Sam being turned into a baby sea creature. After all, things like that just didn't happen right?
"I'm serious Bobby. I don't know what did it but Sam is no bigger than my hand and can't stay out of the water for more than 10 minutes or he starts to get sick. He speaks baby talk and has a tail and webbed fingers." Again there was silence from the other hunter. "Bobby," Dean snapped.
"Look I don't know what to tell ya Dean, I haven' got a clue what could do that to Sam. Something powerful though."
Dean let out a frustrated sigh, running a hand over his face. "Gee thanks Bobby, couldn't have figured that out myself." He paused for a moment. "If you can think of anything give me a call yeah?"
"Course Dean."
With that Dean closed the phone and looked back at Sam who was peering at him from behind the glass. He gave his little brother a small smile and went over to him, bending to look at Sam from behind the glass. "I'm alright Sammy," he told his little brother before scooping him up and out of the tank, placing him back in the bathtub. He figured the more Sammy got the chance to play, the more likely that he would sleep tonight.
The little merman happily swam around chasing after the ball Dean had dropped into the water. The familiar sound of the rushing of wings caught his attention and he glanced over to see Castiel standing behind him, looking at the little creature in the bathtub with what seemed to be curiosity. "Hey Cas…" Dean said giving the angel a tired smile. Just as Castiel was about to answer a stream of water hit his face. The angel blinked stunned and the pair of them looked at Sam who was hiding behind Dean's hand that was in the water, an angry look on his tiny face. Dean couldn't help but laugh, something that as soon as he did it he knew that he had needed. "Guess he doesn't like you angel boy."
"No…he does not appear to…" There was a hint of distaste in Castiel's voice as he stared at the little merman in the tub. "I am guessing that that is Sam?" Dean nodded and watched as Castiel cautiously got closer, kneeling down beside Dean only to get splashed. He wiped his face on his sleeve and gave Sam a stern look, only to have him swim and hide behind his rubber ducky. "I have an idea about who could have done this, just give me a couple of days Dean." Before the hunter had a chance to respond, Castiel was gone.
His eyes turned to Sam who was peeking over the duck to look at him, and it brought a grin to Dean's lips, twirling his finger in the water. "You'll see Sammy soon you'll be back to normal." He watched as Sam tugged on his finger, looking up at him with big pleading eyes. "What?"
"Play!"
"I am playing with you Sammy."
Sam tugged on Dean's finger again and again until a spark of realization lit up the older Winchester brother's face. "Alright if you really want me to…" he said and stood up, stripping down to his underwear before climbing in the bathtub. The water splashed up the sides of the tub as he sat down, Sam swimming around happily, clearly glad that his brother had decided to join him in the tub.
Dean watched as Sam swam around his feet, laughing as his little brother jumped and grabbed onto his knee. "Nice job Sammy," Dean said, earning a smile from Sam. He picked Sam up in his hand and held him close to his face, his little brother hugging him with his tiny arms. "There now how about we play with the ball again hm?" Sammy clapped his webbed fingers again as Dean placed him back in the water and picked up the ball. He dropped it into the water only to have Sam throw it back at him. There was a smile on Dean's lips as they continued their little game of catch.
At least he has the vocabulary of a little kid, Dean thought, unable to keep himself from smiling as he watched his brother nibble the peach happily. "So you like peaches huh?" he asked and smiled at the look on Sam's face. Dean lay down on the bed, watching as Sam swam around the tank after eating his peach, before his little brother lay down on the gravel, using his arm as a pillow as he looked at Dean. "I don't know how this happened Sam, but I promise I'll figure something out…"
After a moment Dean sat up and dipped his hand back into the fish bowl and, once Sam was in his hand, scooped him out of the bowl and made his way into the bathroom. He knelt by the tub, glancing at Sam who was peeking over his palm down into the empty basin. Dean turned on the water, making sure it was warm, the perfect temperature, letting Sam touch the water before his brother slipped off his hand and into the slowly filling tub. Dean stood up and left the room going over to the bag and taking out the rubber ducky, going back into the room to find Sam swimming.
"Sammy I got you a present," he said and knelt down by the tub, Sam swimming over to him. Dean set the duck down by Sam, who poked at it with his webbed hands, causing the toy to bob up and down in the water slightly. The little merman let out a giggle and jumped on top of the ducky, his arms wrapped around the duck's neck as he floated on it. Dean gently pushed it, allowing the duck to move through the water, causing Sam to once again to giggle. "Hold tight Sammy…" Dean said as he moved his hand in the water, causing waves to bounce the duck.
The giggles of joy that came from Sam were, needless to say, adorable and Dean was enjoying himself playing with his little brother and the rubber duck. Sam just seemed so small and vulnerable, like a little baby that needed his protection in the most desperate of ways. Dean was determined to keep Sam safe from everything that could possibly harm him while he was in that state, his baby merman brother

Day Five
Even though Sam hadn't gotten any bigger, Dean had gone out and bought a larger fish bowl, and a fish to go in the tank. His reason behind buying it had been that so Sam would not be lonely when Dean had go to out someplace. Now, the new tank was set up with the fish in the bowl and Dean had just put Sam in it. His little brother was swimming around looking curiously at the small treasure chest that had come with the bowl.
Sam looked up, took one look at the fish that was now swimming in front of him and leaned back away from it, his little eyes wide with shock. Dean shouldn't have laughed at all, but he found the whole scene cute watching as Sam tried to get the fish to play with him, but it only swam around the bowl. The fish ignoring him was something that Sammy did not seem to appreciate at all as he sat on the bottom of the tank pouting at Dean. "Sorry buddy it was get you a fish or put you in a tank with a frog," Dean told Sam as he went about opening the can of peaches which Sammy saw and went right to the surface holding his hands out eagerly.
Carefully, Dean gave Sam the piece of fruit, and then picked him up in his hand letting him eat. "Alright you bath time." The look of annoyance on Sam's face made him grin as he brought his little brother back into the bathtub and picked up a small child's toothbrush he had gotten. The water in the sink was already warm and soapy as he dipped the brush in it carefully scrubbing Sam with the toothbrush. Sam seemed to actually like it judging by the purr that came from his brother. It was a couple of minutes before he let Sammy down into the water in the sink.
"Tub!" Sammy chirped happily looking at the tub with longing eyes. "Tub!" Dean picked Sam up and placed him in the tub, turning on the water and filling it up. Sam seemed very happy as clapped his webbed hands, splashing in the water before he tugged on Dean's hand. "In."
"Only because you asked," Dean said with a smile at his little brother, stripping down to his boxers again before he got into the tub holding Sam in his palm. His brother hugged his thumb, kissing it before he grinned up at Dean, jumping into the now full tub of water. And that precise moment was when Dean heard the flutter of wings and glanced over to the entrance of the bathroom, seeing Castiel, a confused look on the angel's face. "Hey Cas."
"Dean what are you doing?" he asked, a hint of disapproval in his voice, looking from Dean to Sam and back again, arms folded over his chest.
"Playing in the bathtub with Sam, what does it look like Cas?" The angel just shook his head. "What is it?"
"Found a lead, Sam could be back to normal as early as tomorrow night." Castiel paused look at Sam who seemed to have puffed up his cheeks, and he took a step back. "I will call you if I find out anything else." Just as suddenly as Castiel appeared he was gone with a rush of wings.
Dean looked down at Sammy with sad eyes, he had unknowingly become quite fond of protecting and caring for his little brother, and he had even enjoyed it. The moments over the past few days even though at first he had thought he would completely hate it. Playing with Sammy in the bathtub, the rubber duck, watching him eat the peaches and talk with baby talk. And as he watched Sam swim, as much as he wanted to continue to watch Sammy have him be small and act similarly to what he had when they were little, he knew that Sam had to be returned to normal.
It was another couple of hours before he and Sam were settled down for the night, Sammy sleeping on the bottom of the fish bowl that rest on the nightstand, his little thumb in his mouth and Dean lay beside him on the bed just watching his little brother till he eventually fell asleep. The night held dreamless sleep for Dean, at least for the first part of it; the next was filled with memories from when Sam was a kid, and how Dean always took care of him no matter what. That was his job, his first and foremost responsibility, to protect Sammy, his baby brother. How had he been so blind to see that?
The next day Dean spent the entire time in the bathroom with Sammy watching and playing with his little brother, knowing that soon this would all come to an end and no matter what, even if Sam didn't remember any of it, he would be a better brother for him. It was, all in all, a relaxing day, nothing major happened and the only time that Dean left Sam's side was to go get food for himself and even then he rushed right back to Sam. It was as if Sam could sense that Dean was feeling nervous, as he never strayed very far away from him while in the bathtub, even if it was just clinging to his hand.
Nighttime came and Dean paced back and forth, Sam asleep in the fish bowl on the nightstand. Where the hell was Castiel? He should have been there by now… The more minutes that came and went, the more nervous Dean became, slowly bordering on frantic when Castiel and the last person he would have expected appeared in the room. Castiel was gripping Gabriel's arm tightly, glaring at his brother as he pulled him forward. "Fix it Gabriel."
"Cassie seriously you gotta lighten up, it was the best way to teach the hard head here a lesson," Gabriel said tugging his arm away from his brother's grip, placing his hand on his hip, rolling his eyes. The arch angel turned his gaze to Dean, and smirked at him. "Was going to change him back tonight anyways you certainly have learned your lesson."
"What the hell are you talking about Gabriel?" Dean snapped, his eyes blazing with rage towards the former Trickster. "What lesson?"
"Jeeze Sam really is the smart one isn't he? Well Dean, the lesson that you can't stop being someone's big brother and your little brother comes first. You learned it again, bravo, good job."
"You son of a b****…"
"Don't say such harsh things about Castiel's mom Dean." The smirk had stayed on Gabriel's lips, as he held up his fingers ready to snap. Dean, however, could feel the anger radiating off of Castiel, the angel was probably humiliated that his brother would do such a thing, or say something like that. "So tell me Dean should I turn Sammy back now?"
Dean nodded, and the archangel snapped his fingers together. The next thing Dean knew, it was the next morning. His eyes snapped open and he sat up, his eyes turning to the bed beside him, which was empty. Where was Sam? His heart was racing thinking that Gabriel had played a dirty rotten trick on him, when he saw the fish bowl that still had the fish in it and the door to the bathroom opened to reveal Sam.
Sam looked at the surprised look on Dean's face as he toweled his hair dry, having just come out from a shower. "Damn Dean you look like you haven't slept in several days… And why do you seem so surprised to see me?"
"Sammy…what was the last thing you remember?"
"It's Sam and falling asleep last night. Why?"
There was a smile on Dean's lips as he shook his head and stood up, pulling Sam into a tight hug, ignoring his little brother's protests (and the fact that Sam was in nothing but a towel). After a moment, Sam gave his brother a one armed hug, sighing softly. "Dean what's up? Not like you to give out hugs at random or for no reason."
Dean pulled back and smiled at Sam. "Just glad you are here with me Sam," he said and winked at his brother going over to the bed and sitting down to pull on his shoes, having slept in his clothes last night. "Get dressed we're going out."
"Where?"
"To get some pie where else." Dean shot Sam a grin, his brother simply rolling his eyes in response. "Peach pie perhaps…"
"Sounds like a plan." With that Sam got dressed, and the brothers left the motel room for the nearest diner, in search of peach pie. Sam's eyes had seemed to sparkle at the idea of peach pie, and Dean knew that deep down Sam knew what happened whether or not he could remember, but that sparkle told him that his brother knew. And that made Dean happy, cause the one thing he wanted was to be able to be the big brother that his Sammy deserved.