Author's Note: Well, hello there reader. This fic is... something. This is a prompt, given by a tumblr user. It was such a fun idea to think about that I decided to go with it. And here's where it gets fun-this is my first Sherlock chapter fic. Whoa! What! You? Doing a chapter fic? You may be saying to the screen right now (more likely though, you aren't. Because that's an irrational reaction. Ha.) It won't be a long chapter fic, admittedly, but it will be broken up into chapters.

So for those of you who have been asking me to do something longer: you're welcome and I hope it's up to your tastes.

As always, thanks for reading.

When John woke that morning, he didn't open his eyes right away. Guilt was pinging around somewhere in his stomach, recanting the previous nights argument with his flatmate. He watched the scene dance across his eyelids-the way Sherlock had shouted, the words that fumbled from his own mouth, the fleeting look of hurt that had made its way into Sherlock's eyes-and he exhaled. Neither of them had been right, of course. Both had said things they probably wouldn't have said had temperaments been cool...

Slamming doors, raised voices. Sherlock flings his coat off of him, tossing it carelessly over the couch. John is fuming. He's seeing red when looking upon the tall man before him. He too strips out of his coat, but his hands are shaking as he does so. He practically tears the coat off of him, words flying from his mouth.

"You couldn't resist, could you? You couldn't help being a dick for just a moment." he says loudly. He's shaking his head, his heart is racing, he's ready for a fight. He's asking for it. "Always out to prove how much more clever you are than everyone around you." he shakes his head. "When, lets face it, in reality you aren't really all that much more clever."

Sherlock swings around. His eyes are cold and his face is tight. "As though someone like you is applicable to make such a judgment." he hisses. John glares at him. "Someone like me?" he asks, incredulous. "What do you mean, someone like me?" His hands are balling up into fists, almost instinctively. Sherlock sneers, eyeing John quickly. "Precisely. Someone like you. Someone with no foreseeable extraordinary talents. Another typical peon, comparatively."

John's mouth gapes. "A peon? As though you're some sort of God or something?"

"Let's face it, John. You've no place to rank my intelligence. Those more intelligent, perhaps. Even those who are equal may take part in deciding where I stand intellectually." His voice is hard and informative. It takes every piece of restraint John has in order to keep from landing a clean punch into Sherlock's supercilious face. "But you? Your opinion of me holds little importance."

"Oh, so you think I'm an idiot, is that right? Some kind of blundering imbecile, running about-"

"To put it so very eloquently, yes."

John laughs a malicious laugh. "At least I know I'm human. I face my fears head on, I feel everything in the world around me. I'm not the one too cowardly to love or hurt or dislike or try." he says. His voice has gone almost giddy. "At least I'm not daft enough to believe I'm above being a human being. You?" he laughs again, and it's one that's filled with pity. "You say you divorce yourself from feeling those things, because it helps your work? No. No, you try to 'divorce' yourself from those things because you're afraid. You're too scared to feel." He shakes his head, a look of something between disgust and pity on his face. "You're a coward. A stupid coward."

Sherlock's begun shaking. John's words have struck a chord, he can see it now. It warrants a self-satisfied smirk to cross his lips as Sherlock's cool demeanor falls. "You know NOTHING." Sherlock shouts. "You... you know absolutely nothing of me! Don't for a moment think you've figured me out, Watson." He's shouting. He takes two large strides and he's face to face with John. "You say what suits your needs now, but don't think for a moment you've cracked the code. You are just another person, another stupid human being. Another hindrance." He hisses.

"Another hindrance? Is that what I am, another roadblock on your stupid bloody path?"

"Did you figure that out all on your own?"

John's face comes closer to Sherlock's, so close Sherlock can feel his breath against his face. "You think you've got everyone figured out? You think you've got me figured out?" he growls. "You are the one who knows nothing. You need me."

Sherlock backs away. "I don't need you."

"Oh, you do Sherlock. You do." John says, shaking his head. "But then again, you'd be too afraid to admit that as well, wouldn't you?"

"I DON'T need you!" Sherlock shouts. John doesn't reply as he makes his way from the room. He's done arguing. He refuses to continue on. Sherlock shouts it again. "I DON'T NEED YOU." but John is already making way up the stairs into his room.

John sighed. He'd have to apologize. He hadn't meant any of the rubbish that had spewed from his mouth. The problem with arguing with people like Sherlock was that they always knew just what to say to throw him over the edge. They knew just the right buttons to push, in just the right sequence, to cause him to be so... he sighed again. Sherlock would surely still be seething. John would have to be the bigger man.

He sat upright finally, heaving a deep breath as he did so. He opened his eyes, momentarily dizzied by the sunlight basking in the room.

Something wasn't right.

His eyes roved the room quickly. He realized what wasn't right about the room. It wasn't his. He glanced from the foot of the bed to the dresser. From there, to the wall hangings. The periodic table? No, not his room at all. Sherlock's room. Sherlock's room? He panicked. How in the hell had he come to wake in Sherlock's room, in his bed? Sherlock wasn't there, that was for certain. But then... John shut his eyes, rubbing his hands over his head.

That didn't feel right.

His eyes shot open, slowly running his hands over his head once again. He crept his fingers into the hair upon his head, grabbing hold of a lock of hair near the front. He pulled it down before his eyes and revealed the dark strands to himself. "No." he said, but the moment he did so, his hand clasped over his mouth. That wasn't his voice.

"Hello?" he said. Only, he didn't say it. The voice that emitted from his vocal chords was a deep rasp. Not his.

He flipped the comforter from him and stood quickly, striding toward the hook upon which one of Sherlock's dressing gowns hung. He wrapped it around himself, realizing all too suddenly that he was taller. He was taller. John had been the same height since he was sixteen. He looked down to the hands that tied the rope around his waist-long, slender fingers. Pale. He sighed, some kind of fear creeping up into his body. What was going on? How could he...? He flung open the frosted glass panel door, stalking into the restroom.

He looked in the mirror, leaning over the sink and staring hard.

He shook his head, shutting his eyes, attempting vaguely to possibly shake the sight from it. That couldn't be right. There was no way. There couldn't be a way.

He opened his eyes and looked to the mirror again.

Blue eyes, light, almost gray in the bathroom's dim lighting. Cupid's bow shaped lips. Sharp, sharp cheekbones, high upon his face. Dark mop of curls atop his head. Pale. Long neck. He stood upright. He turned his head, looking at the profile. "No." he said to his reflection.

It was Sherlock he was staring at. Who was, in fact, staring at him, in the reflection of the mirror before him. John gulped, and so did the reflection of Sherlock. John raised his arm, and so did Sherlock. He could hear the crashing of feet rushing down the stairs, and when he turned his head to look out the open restroom door, Sherlock did the same.

"John!" he heard Sherlock call. Only, it wasn't Sherlock's voice. It was his.

It was even more bizarre to see himself (God, was he that short?) bounding angrily down the hallway into Sherlock's room. He stopped, rounding toward the bathroom door, where John (or was he Sherlock? This was getting confusing.) was standing. He stared at himself. "What... has happened?" Sherlock said. But it was John's voice, coming from John's body. It made John's-the real John's-stomach twist. "I.. I don't know." Sherlock's voice said.

"You've taken my body." John's voice replied.

"How in the hell would I have managed that? I'm not an evil genius and this isn't a fairy tale, Sherlock." John said defensively. The words sounded strange coming out in Sherlock's telltale throaty growl.

Sherlock held his hands up, a signal that asked for silence. "Alright. Alright. Just... just give me a moment." he said. He blinked, inhaling deeply and exhaling slowly. "We're both still ourselves. I'm still in possession of my mind, at any rate. And you obviously still have yours. So then our identities remain. The thing that has changed, however, is our physicality." he looked back up to John. "You seem to have taken on my body, and I have taken on yours."

"We've switched." John replied simply.

Sherlock rolled his eyes dismissively. John wasn't sure he'd ever actually pulled that face while he'd had his body. It was weird, seeing him look like such a know-it-all. Then again, with Sherlock in current possession of his body, it seemed he might be getting to know the face a little better.

Then John had a strange realization.

"Sherlock, I've seen this before." he said. His eyebrows furrowed, his lips parted thoughtfully. He held up a single hand, allowing the thought to sink in. Sherlock stared at him, bewildered. "You've... you've seen this? John, this isn't even medically possible."

"No, no. Not in that way. No." John's eyes widened. "Sherlock, this is from a film."

"A film?" Sherlock asked incredulously.

"A film. An older film." The thought was crashing through his mind. He could remember it very vividly-a mother and her daughter not seeing eye-to-eye, a mysterious switch of the bodies, a day lived as one another. He looked back to Sherlock. "Freaky Friday." he said. It was strange to hear Sherlock's voice say the name of such a film.

Sherlock's eyebrows furrowed. His face contorted into disbelief. "Freaky Friday?"

"Yeah, yeah. It's a film. Been done a few times." John said with a laugh. Sherlock's eyebrows furrowed harder-it must have been just as strange to see himself laughing so freely. John shook his head, "Tell me you've seen it."

Sherlock shook his head.

John rolled his eyes, finally stepping from the bathroom. He pushed past Sherlock in a truly Sherlock fashion, making his way into the living room and onto his laptop. As quick as he could, he pulled up information about the movie. Sherlock had followed him, looking over his shoulder. "I can't believe you've never seen this film." John said with a shake of his head. "See, look." he said, pointing. Sherlock leaned over farther, his eyes quickly dashing over the screen. John watched him. It should've confused him more, to find himself in Sherlock's body, watching Sherlock in his, but somehow the initial shock had worn itself off.

Sherlock stood finally, his hands upon his hips. "They have a disagreement and switch bodies until they each have some kind of revelation conclusive to one another's thought processes." he said, a note of disinterest in his voice. John turned in his seat, facing Sherlock. "That doesn't ring a bell?"

"I've never seen the film, John."

John rolled his eyes. "No, not what I meant Sherlock."

Sherlock's tongue slid over his teeth thoughtfully, pursing his lips just so. He glanced around the room, eyes dancing quickly over the furniture and the floor and the walls. His coat was still lying across the couch. He turned back to John slowly, his eyebrows raised high. "No." he said.

John quirked an eyebrow.

Sherlock shook his head. "No... it's not scientifically possible." he said slowly. He looked back to the coat on the couch. John knew from the look in his eyes that he was reliving the previous night. His brain was raking over every moment. Then he shook his head again, giving an irritated scoff. "Brilliant. So you're assuming we've been punished for having a row, and won't return to our normal states until we've seen each others perspectives, is that right John?"

"Any better ideas, Sherlock?"

For once, Sherlock had none.