This is an au where Tom and Harry are in the same year at Hogwarts. Their backstories are basically the same, except it was Grindelwald that killed Harrys parents, and he never comes back after that.

...

Harry listened to another one of Tom's long spiels as they sat together in an abandoned classroom. It was less dusty than the other abandoned classrooms in the castle, mostly because Harry and Tom had been using it as their meeting place for almost two years. Tom was talking animatedly, waving his hands and speaking loudly, trying to get his point across to Harry.

Harry, on the other hand, had heard this speech before, and already had his reasons for his disagreement with it. He let Tom go on for a while, but eventually cut him off, "No, Tom, we can't." He felt like they were having the same argument over and over, as he shot down Tom's suggestion once again.

Tom just scowled and continued on. "I really think we should-" Harry sighed rather loudly, cutting him off and repeated once more, "No, we can't. You know why."

Harry turned away, back to his essay trying to signify the end of their conversation so they could put the touchy subject behind them, but Tom ignored that and scooted closer, "Harry, come on, you know that's a stupid excuse. They're your friends. They won't care. Or, well, if they're your friends they shouldn't care."

Harry frowned, looking back at Tom. They'd had this conversation too many times before, but Tom never seemed to understand. "You don't know what they're like, they really do hate you."

Tom scoffed, "Hate me? Why would they hate me?" Harry rolled his eyes and then looked pointedly at Tom's Slytherin tie. "Oh, I don't know... according to Ron, you're 'a stupid, pompous little git' and that's just Ron's opinion... Hermione isn't very impressed by you either."

The Slytherin just waved a hand dismissively, "Oh, you know Granger only dislikes me because I'm above her in all our classes. And Weasley is just an idiot, why are you even friends with him?"

Harry rolled his eyes at that comment. "Ron is not-" he was cut off when Tom put a hand over his mouth and used his other hand to pull Harry closer to him in the small bench they were seated on.

"Ah, don't, I know what you're going to say…" Tom's hand slid off his mouth, as the Slytherin scrunched up his face in an unflattering manner and attempted to imitate Harry. "Ron is not an idiot! He's wonderful and he is my best friend!"

Harry gaped at Tom's playful and mocking demeanor, "You got it all right, but, I do not sound like that!" He said, pretending to be offended even as he laughed.

Tom smiled at his reaction and then gasped, "Wait a second, somethings not right here…" Tom narrowed his eyes at him suspiciously and Harry did his best to look innocent. "I call Weasley an idiot and you immediately defend him? What did you do when he called me a pompous git?"

Harry grinned at this, moving slightly farther away as he responded, "Oh, I agreed with him. You definitely are a pompous git."

Tom let out an exaggerated gasp and grasped his chest, "Choosing your friends over your lover! You wound me Harry!" Harry laughed as Tom pretended to look devastated at his 'betrayal'.

"Shut up, you know you're a pompous git, and you're proud of it, stop pretending." Even as he said it he couldn't stop the small laughs from coming out as Tom gave him a wide smile. He always loved seeing Tom so carefree and happy, and he liked to think he was more of those moments since they had gotten together.

"Hmm, yes, I am rather…egotistical, but I'm also Head Boy, and I'm at the top of all my classes, and I've been told that I'm very good looking...so I think I'm entitled…You know what? You're lucky to have me, Harry Potter." Tom paused in his shameless gloating and reached his arms out to drag Harry closer again.

This time, Harry was pulled straight into Tom's lap with a small squawk of protest, and Tom turned them around so he could lean against the table they had been working at and Harry could lean against him.

Harry settled down into his lap comfortably and Tom gave him a kiss on the head before trailing his lips down the side of his neck and resting them at the small dip in his neck. "And I'm lucky to have you..." he said lowly, his mouth pressed softly against Harry's slightly tanned skin.

The green eyed boy hummed in contentment and Tom tilted his head back up slightly, before letting out a small dramatic sigh. "Unfortunately, nobody knows you're mine because we have been sneaking around the past two years." He said the last part loudly, as if he was trying to announce it to the whole school, even if they couldn't hear him.

Harry groaned at this comment and tried to stop this whole conversation from happening again. "Tom-" he was interrupted by Tom's rather loud and questioning response, "No, Harry, I don't understand! Why are you so against this? Why don't you want to everyone to know we're together?"

Harry went to answer him, but apparently they were rhetorical questions because Tom just continued on. "I mean, just imagine, Harry. Having everyone know of our relationship... we could eat in the great hall together, walk to class together, I could kiss you in front of everyone, show them you're mine..." He trailed off and leaned back seemingly lost in thought.

Harry sighed and leaned back onto Tom. It did sound very appealing, even if half the reason Tom wanted to come out was because he wanted to be able to keep people from continually pursuing Harry.

He knew that many people would love to be with him, mostly because he was the 'Boy-Who-Lived' and had apparently survived a killing curse as a baby and destroyed the dark lord Grindelwald. That alone made him fairly famous. Never mind the fact that he managed to be the youngest seeker in over century, having gotten the position when he was just a first year.

Tom also complained frequently that people other than him were starting to notice the fact that Harry was growing out of the scrawny boy he used to be. He was still short and almost everyone in their year towered above him, but Tom said he was small in the most adorable way, and other people were starting to notice that too. Of course, he later denied ever saying the word adorable, which was fine by Harry because then he could deny ever being called adorable.

Tom's possessive and jealous nature was sometimes annoying, but mostly it endeared Harry how worked up Tom could get over a small, even slightly suggestive glance his way. Of course, no matter how worked up Tom got about any leering passerby's, Harry never him do anything about it, which he was sure was a main part in his frustration over keeping their relationship a secret.

There was silence in the room for a while as Harry leaned his head back on Tom's shoulder, contemplating all of this, and Tom absently ran a hand through his messy black hair. Eventually, Harry decided to speak up. "I know," he paused for a second, trying to find the right words to say this, and have Tom understand, without being an asshole about it. "I know you want to come out. And I do too, I just... I need more time... Ron and Hermione don't even know I'm gay, so how am I supposed to tell them I'm dating their least favorite Slytherin who just so happens to be a man named Tom Riddle?"

There was more silence as they both seemed to think through this, and then Harry started up again, "And, I'm supposed to be the 'Boy-Who-Lived' and all that crap. What are people going to do when they find out I'm dating a Slytherin? I get stared at and bothered by people enough as it is. We've made it almost two years like this, and we are going to graduate soon anyways. Why not a little longer?"

Tom, who had had his arms draped loosely around Harry's waist, tightened his grip and kept his mouth near Harry's ear as he said quietly, "We both know that's not the whole truth about why you don't want to go through with this. You're scared. Come on love where is that Gryffindor courage of yours?" Harry stiffened slightly at Tom's words knowing he was just trying to bait him into another one of his impulsive decisions, and hastily made to get up. He shook himself off of Tom's tight embrace, ignoring Tom's small noise of protest.

He started to gather up his things and pack them into his bag muttering about it being dinner soon. Tom sighed at his lover's stubbornness. "Harry-"

"No, Tom, You don't know what it's like... you don't understand...I don't want... never mind. Let's just go. We're going to have to be a dinner soon, and I'm sure Ron and Hermione are starting to wonder where I am." Tom huffed at being dismissed so rudely and watched as Harry snatched up his bag and darted out of the room.

Tom was left sitting there wondering what he would have to do to get Harry to agree to this. Harry repeatedly complained that Tom didn't understand that being the famed 'Boy-Who-Lived' was a chore that would only be made more difficult if he revealed he was gay and dating Slytherin's heir.

Tom sat there all through dinner, knowing he could just go to the kitchens for something to eat later. He stared at the wall intently, trying to conjure up a foolproof plan to get Harry to agree with him. When it was time for him to get back to the Slytherin common room a couple hours later and he finally gathered up his work and grabbed his bag to leave, he was walking out with a small satisfied smile and a brilliant plan.

...

The next day, Tom was studying quietly in the library at his usual corner in the back when Harry hesitantly approached him and plopped down in a nearby seat. Tom had a brief moment where he wondered how managed to fall in love with such an unrefined Gryffindor, but he brushed that thought aside as Harry proceeded to take out his wand.

Harry smiled shyly at him and cast a silencing charm around them before tucking his wand back into his back pocket. Tom's eye twitched slightly in annoyance at seeing that. He had repeatedly told Harry not to stuff his wand in his jeans pocket, and Harry had repeatedly ignored him. Harry was such an infuriating and stubborn person, it was a wonder that Tom put up with him at all.

He watched as Harry got increasingly more nervous as time went by and Tom had yet to greet him. He was biting his bottom lip unsurely and bouncing his knee slightly in his unrest, and Tom allowed a small smile to creep into his face as he observed his lovers endearing habits. The smile didn't fade, even as he told himself that he was supposed to be angry- or at least pretending to be angry- so that he could unnerve his dear Harry before coercing him into going along with his scheme.

Harry glanced up briefly, and brightened at seeing slight upturn of Tom's lips and his amused and somewhat fond expression. Harry straightened up a little more at sighed softly before finally speaking up. "Tom, I'm sorry for yesterday... I didn't mean to be so rude... Why weren't you at dinner?" Tom let his smile grow wider at the apology. His little lover was so predictable. Of course, he had expected to be avoided a while longer before the apology came, but the fact that Tom had skipped dinner seemed to up the guilt factor for Harry.

He flipped a page in his book nonchalantly as Harry watched him intently, waiting for a response. He merely shrugged his shoulders. "Oh, I just had a lot to think about... a lot I needed to plan..." Harry suddenly took on a nervous demeanor. Whether it was because of the way he had worded his answer or the mischievous smirk that followed it, Tom didn't know, but he delighted in seeing his Harry squirm in apprehension at his response. Of course, seeing his lover squirm in pleasure was his favored view, but this had to be the next best thing.

Tom's smirk only grew as Harry got out his next sentence. "Planning? What did you need to plan?" His lover's nose scrunched up in the most adora- attractive way, seemingly confused and slightly worried. Tom just chuckled and set his book on the table gently, "I am so glad you asked my dear Harry!" One look at Tom's delighted and devious expression was enough to have Harry regretting all of his life decisions.

…

After Harry's enlightenment on his horrible life decisions and a rather abrupt end to their short conversation, Harry ended up not seeing Tom until that night, at midnight. Tom had ended their talk with a request to meet him at the entrance of Salazar Slytherin's Chamber of Secrets in the girl's bathroom.

They had discovered the chamber in their sixth year, not completely on purpose either. They had officially met each other in an awkward way during their fourth year. Harry had been out on the grounds, conversing with some of the magical snakes (because what else do you do when you're having problems with your friends and have no one else to talk too?) when Tom came upon him, thus revealing Harry's parseltongue secret and spiking Tom's intrigue. Tom had promised not to tell anybody else his secret, so as long as Harry admitted to how he had parseltongue in the first place, because as far as Tom knew, he was the only Slytherin heir.

Of course, Harry had absolutely no idea where his parseltongue abilities came from, which sparked a year of reluctant friendship and secret research. In the end, it was found that he had had the dormant parseltongue gene and it had activated in him due to a mixture of his mother's blood sacrifice and the killing curse that had struck him as a baby.

The explanation for this had made Harry's head hurt, so he didn't try to understand it, but it seemed to placate Tom. By then, though, their friendship had turned into something more and they continued to meet each other in secret. They had started searching for the Chamber of Secrets of that, wanting a better place to meet than the old abandoned classroom, and occasionally the Room of Requirement.

After finding the chamber though, (which had been a rather awkward accidental discovery that had included a heavy snogging session on the bathroom sinks) they had opted to stay in their abandoned classroom, mostly due to the fact that there was a giant ass basilisk in there. The basilisk- who called herself Kali- was friendly really, but she had a tendency to forget that her eyes and fangs could easily kill them, and neither of them really enjoyed the idea of getting accidently murdered by a well-meaning basilisk.

Harry reminisced for a while as he waited for Tom to show, silently debating whether or not he should just go into the chamber first and wait for him there. The silence in the bathroom as he stood there alone was disconcerting and he would much rather be down in the chamber where he knew he wouldn't be caught by any teachers and he could converse with Kali.

The only reason he stayed waiting at the entrance was because he knew Tom got anxious and paranoid when he was in there with the basilisk by himself, even if he would never admit it. Tom seemed to have a strange paranoia concerning either of their deaths.

He was feeling slightly curious about the plan that Tom had hinted at, despite the fact that he knew it could be nothing good. Well, nothing good for him at least. He was sure the Slytherin would only propose a scheme that happened to benefit him in one way or another.

Harry cast a quick spell to check the time and huffed at seeing that it was fifteen minutes past twelve. If Tom was going to request a meeting somewhere he should at least have the decency to show up.

Five minutes later, Harry was tapping his foot impatiently when Tom finally showed. He had a wide grin on his face and a think tome under his arm. Harry quirked an eyebrow at him, "how nice of you to show up."

Tom just brushed him off, still grinning madly. "Oh, I had important things to finish before coming." He held up the large book to him. "Needed to get what I needed for my brilliant plan." Harry nearly rolled his eyes at his boyfriend's utter lack of modesty and stepped aside as he went to open the chambers entrance.

Tom hissed a soft, "open" and as the chamber slid open, Harry hissed "stairs" and allowed himself a small smug smile at the slight darkening of Tom's eyes. No matter how many times he heard Harry speaking parseltongue, he never got over his obsession about the fact that they had their own secret language. It had always seemed to spark the possessiveness in him.

Harry started to step down the dark stairway first, whispering a soft, "lumos" to light the way. Tom was right behind him, gripping onto his arm as they went, as he did every time they entered the chamber. He seemed to have the idea that Harry was incapable of handling himself responsibly around a deadly basilisk and hanging tight onto his arm apparently made him feel better about it.

Tom's illusions to Harry's incompetence might be because he had once found him taking a nap in Kali's coils. He hadn't reacted very well to that, if the ranting and raving about stupid reckless Gryffindor's was anything to go by. But honestly, Harry wasn't stupid enough to cuddle up with the basilisk again, especially after facing Tom's wrath. Her scales were a bit uncomfortable anyways.

They continued walking down the steep steps in without talking, only the echoing sound of their footfalls and their breathing breaking the silence. Once they were at the bottom, and had entered the main chamber, where the basilisk usually resided, Tom steered him away from the slumbering Kali with a determined expression and lead them towards the other door.

Harry complained loudly at this. "Hey! I wanted to say hello to Kali!" Tom shook his head, grasping onto Harry's hand a little tighter as they went. "No, not now, Harry. We have much more important matters to attend to." Harry sighed resignedly and let himself be pulled along onto the separate chamber, grumbling a bit about the fact that he hadn't gotten to speak with Kali in a while.

They made their way over to the library that resided in the corner of the chambers and Tom set the book he had been carrying on a small table before turning to a steaming cauldron that sat nearby. He started to tend to whatever potion was brewing in there, stirring slowly with a concentrated look on his face and Harry stood there awkwardly. "Um, Tom?" Tom just hummed in acknowledgement and continued stirring. Harry huffed and sat himself on one of the chairs, watching Tom curiously. He had always been horrible at potions, but Tom was the best in every single subject, and he had to wonder what sort of potion warranted secret brewing down in the chamber.

"What are you brewing?" he asked slowly, hoping Tom would finally give him some answers. There was a few seconds of silence before Tom stirred one last time and Harry watched as the potion turned a bright green. Tom stood up straighter and beamed. "This, my dear Harry, is a special potion that I found a while ago, right here in Salazar's chambers."

Harry raised an eyebrow at Tom's proud declaration and prompted him to continue. "Ok, what does it do?" Tom gave a rather devious smirk at that and Harry wondered whether or not he should start running. Despite Tom's obvious eagerness to explain his newly brewed potion fully, he seemed set on dragging the explanation out into a long monologue. Which Harry should have expected, really. Tom was always one for dramatics.

"I never thought I would ever need to use this potion, seeing as it requires consent from both recipients and a drop of blood." Harry's eyebrows rose impossibly higher at that statement, now feeling even more curious, as well as apprehensive to learn what the potion was, and how it pertained to Tom's plan. "It is a potion similar to the polyjuice potion, and I intend to use it both of us." Tom paused to observe Harry's reaction, which was suitably horrified.

"Similar to polyjuice potion, but requires consent and blood," he mumbled to himself, "Well, this can't be good."

Tom chose to ignore Harry's comment and opened up the thick book he had brought over with them. "The potion is called corpus verto, and its purpose is to switch the bodies of two people for a day." He slid the open book in Harry's direction and Harry glanced down incredulously at it. "Um, I'm sorry, did you say switch bodies? You want us to switch bodies?" Tom nodded, seemingly unaffected by Harry's rather loud tone.

"Yes, you said that I couldn't understand the things you struggle with, being the famous 'Boy-Who-Lived' and all, so this is my way of trying to get an understanding of it." Harry had to admit that it was rather sweet of him, and Harry really shouldn't have expected anything less from Tom. But then he realized the implications of this. "Wait, so you're going to be living in my body for a day and I'm...?"

Tom chuckled and sat himself next to him, wrapping an arm around his shoulders. "You are going to be in my body for the day." Harry gaped at him. This was all completely insane. "You're going to let me walk around as you?"

Tom sighed, "Yes, so you better not fail my classes, or get caught." Harry made an indignant sound at that and crossed his arms, "get caught? What happens if I get caught?" Another slow smile spread on Tom's face. "Well, you'll have to suffer through the interrogations from Slytherin's and wait for me to rescue you." Harry scowled at that. "Oh? So what happens if you get caught?"

Tom outright laughed at that, seemingly amused at the mere idea of it. "Hmm, I doubt I'll be caught, but if I am I'll have to suffer through the shame of getting caught by Gryffindor's and, well then you will win." Harry felt confused at the last part. "Win? Win what, exactly? I wasn't aware this was supposed to be a competition."

Tom nodded at that, "yes, well if I got caught, or say, gave up, it would mean that I... can't handle being you, and you get to decide when and how we tell everyone about us." Harry blanched at this, "So, if I get caught, do you get to choose when we come out?" The Slytherin shrugged his shoulders at that. "We'll see... but first, are you willing to go through with this?" Tom gestured back towards the finished potion and the open book and Harry didn't even have to really think about his answer, he nodded. He wanted Tom to know how horrible having everyone feel entitled to your life details felt, so he could understand, and if this was the way to do it, then he was going to do it.

Tom smiled widely at his affirmation and hastily got up to get the potion ready and onto separate vials for them. He poured two and set them on the table, before retrieving a small knife from the side table and pricking his finger, letting a droplet of blood splash into one of the vials. Harry watched on curiously as the potion changed into a deep blood red color, and Tom cleaned the knife with a spell before handing it to him. Harry sliced the tip of his thumb and let a drop of blood fall, barely noticing the slight change in color, as his had only turned into a green a few shades darker. Tom smiled at the finished products and Harry observed with anticipation as he downed the vial with Harry's blood.

Harry watched, enraptured as Tom seemed to be savoring the taste of his potion. "Hmm," he mused, and then smirked at Harry. "You taste refreshing and sweet." Harry blushed despite himself and then gasped as Tom's form seemed to shimmer and ripple. He heard Tom groan and then in his place, stood and exact replica of Harry himself. "Wow..." Harry breathed, "This is so strange."

Tom looked down to observe his new body-well, Harry's body, really- and then said, "Wow, I don't think I've ever felt so short before." Harry scowled at that and reached for his own vial, tentatively sipping the dark red potion before drinking the entire thing and turning to grin at Tom. "You taste like a red wine."

Tom had a pleased look on his face at that, and Harry felt a strange sensation that signified the beginning of the transformation. He felt himself grow taller, and when the uncomfortable process was over, he was looking down at his own body scowling up at him. Harry inwardly cheered at the fact that he got to be tall for once in his life and Tom had a sour expression on his face as he complained, "How do you stand being so short every day? Do you always have to look up just to see my face?"

Harry rolled his eyes at this, "Well seeing as you're a little more than six foot and I'm barely past five, I'm going to have to say yes." Tom seemed sulky for a second and Harry smugly stated, "This was your idea. No way to back out now." Tom nodded at that, his face clearing up of any uncertainness and stated, "Oh, yes, I'm quite aware of that. I was just wondering…How kinky would it be for us to have sex like this?"

Harry groaned, "Well, first of all, that's never going to happen. I'm not really up for idea of shagging someone that looks exactly like me. Although, I'm sure you'd be up for it, you narcissistic bastard." Tom grinned shamelessly at that. Harry yawned, beginning to feel the effects of the time of night, and decided that if he was going to have enough energy to deal with the Slytherin's tomorrow, he was going to have to go to bed now. Tom agreed with him wholeheartedly, and they each went their separate ways after trading their common room passwords. Tomorrow was going to be long day.

...

Not sure where this idea came from but I hope you enjoy it anyways...