It's the classic LovePotion!trope. I mean, everybody's gotta try at least one...right? :D

...Well, actually, it's what starts the plot, but...I hope it turns out a bit deeper than that. Slytherin!Harry, Time Travel.

The dungeons chilled the cauldrons, making them startlingly cold to the touch. An undiscovered leak sent drips echoing off the stone, unnoticed by the students who whispered over the sound.

Tom Riddle pointedly kept his gaze directed toward the front of the classroom, listening to Professor Slughorn drone on about love potions, of all things. He held almost unnaturally still, a sharp contrast to the students fidgeting around him, giggling about crushes or shifting uncomfortably with blushes coloring their cheeks. Behind him, a Slytherin girl quietly boasted about her mother, who had invented a variation of love potion which created false, amorous memories.

Compared to other dalliances of which Tom's classmates spoke, it was actually an intriguing invention. Taking into account theories of obliviation and legilimancy, Tom thought the description doable but challenging, especially given that few wizards ever fully mastered the ability to manipulate memories. And if editing them proved difficult, creating them remained positively onerous.

How frivolous, to spend all that time and knowledge developing a love potion. If Tom had his way, he would put such talented witches and wizards to much better use.

Thankfully, his lab partner was not among the fidgeting, giggling masses. As the lecture continued, however, Tom grew increasingly wary of the looks the boy kept sending his way. The boy frequently behaved nervously around him, but surely this was too much. His neck prickled at the unwelcome and intrusive gaze.

He'd puzzled over the grudge for weeks; the boy had enrolled in Hogwarts out of the blue, and he'd taken an illogical and immediate dislike to Tom. His face burned red with anger when spoken to, he avoided Tom whenever in the same room, and the boy always watched him with suspicion. Tom treaded carefully around him, but Potter still snapped at him regularly and tensed whenever he appeared-

Oh.

Tom's eyes widened, the grating mystery of Harry Potter's odd behavior finally solved, a sudden moment of clarity after weeks of speculation.

A smirk played across his lips, his new discovery amusing him so much that he didn't even care if Potter saw it.

Tom recalled the blushing, the nervousness, and the spying, and now he reconciled them to these frequent but covert glances in a lecture about love potions. He'd maintained his facade too perfectly to arouse suspicion; of course the boy didn't suspect. No one ever saw beyond his Head Boy badge, his handsome features, and his suave manners.

The answer was simple: the boy was bent. And he fancied Tom Riddle.

Yes, Tom mused, a schoolboy crush made much more sense than Harry Potter being privy to unattainable knowledge, a sixth sense that warned him of Tom's false persona.

"Tom, you would know the answer, of course?" Slughorn interrupted, snapping Tom irritatingly out of his speculation. Rapidly thinking back over the man's last words to recall the question, he easily recalled the answer from a text he'd read a few weeks ago.

"Bloodroot and its extracts kill animals cells, making it useless in most consumable potions except for poisons," Tom responded mildly. "It can also, however, be used in several healing poultices, Professor."

"Brilliant," Slughorn beamed, clapping his hands together. "Perfect answer, Tom. Five points to Slytherin. I want all of you to keep Tom's words in mind when you start on your potions today, so that you don't exchange bloodroot for the root of aconite..."

Tom tuned the man out again as he went on with the lecture, his gaze flickering over to study the dark-haired boy next to him. He caught Potter's eyes, an unsettling green, before the boy turned away with a scowl.

Before, Tom would have interpreted the reaction as distaste, but now he thought the flush of red might be credited to yearning instead of anger, and the scowl to embarrassment instead of irritation.

The boy desired him. Tom had exploited such feelings before, although he questioned how best to do so in this particular situation. He needed more information on the boy in order to know how to use him most productively, but in reality, he knew little about the him for certain. He suspected he must be the illegitimate child of the Potter family, but the boy had suddenly appeared a few weeks into the year—their N.E.W.T.'s year, no less—and spoke little about where he came from.

Tom suspected he was indeed a part of the old House of Potter, because as another member of Slytherin, he must be at least half-blood, if not pureblood. And he suspected illegitimate because Potter's eyes had positively flashed when Tom had asked him about his parents, back during the early days when he'd been appraising the new student.

Small talk was drab, but it usually did wonders for lessening suspicion and earning trust. Now he realized the reason for Potter's apparent immunity to his charm; he'd been approaching the situation all wrong, like he'd been facing a rival instead of a boy with a crush.

Come to think of it, he had overheard Potter tell Orion that his middle name was for his father. He must have lied, or else he'd taken the Potter name from his mother, because as far as Tom knew, the House of Potter had no "James". He must be ashamed of his mudblood sire. Half-blood, then.

"Well then, off to work with you," Slughorn announced, and the class eagerly started in on the practical portion of the class, chattering about who they'd test the love potion on...hypothetically, no, of course we're not serious, Professor.

Their textbook included several varieties of love potions, and discreetly glancing across the table, Tom saw Potter choose one of Laverne de Montmorency's variations. It was unique in that it did not require consumption, instead activating when applied directly to the skin. Since the substance could not be digested, its effects created only a mild obsession while the victim retained much of their personality, much weaker than the typical love potion.

Usually not chosen because the victim could not always be coaxed into...anything and everything the maker wanted, it did, however, last considerably longer than the standard 24-hour dose. It had been known to last for over a week, although it depended largely on the efficiency of the brew, the body mass of the recipient, and the attractiveness of the maker.

With a thoughtful frown, Tom turned to the same page, preparing his cauldron for an identical potion with practiced ease.

The class continued uneventfully, although he did pause to inform Potter that he'd turned his burner on too high. The boy tensed so badly at his voice that he knocked several ingredients to the floor. Tom Riddle narrowed his eyes at the boy's shyness, wondering if he'd been wrong about Potter's potential value, if he couldn't function properly around him. Much of what Tom had in mind in regards to the boy's serviceability required discretion.

The rest of the class passed in silence, with Tom too busy plotting and Potter too shy. The boy finished the hour with a passable concoction, while his own turned out predictably flawless. Slughorn gushed praises on how he'd never seen a stronger sample of Mollis Caritate.

Tom took the praises with a humble smile and soft thanks, whereas Potter glowered outside of Slughorn's line of vision, probably thinking enviously about how he could never dream to match or claim someone so perfect and brilliant. Tom had certainly heard girls whispering such things on several occasions. The veracity of the thought entertained him.

Slughorn moved on, but Potter's foul mood remained. After vialing a sample of his potion, he cleaned his station with jerky motions, nonetheless efficient despite his abruptness. When he caught Tom watching him, he narrowed his eyes and brushed past Tom just a little bit too roughly, stumbling as a result. Reaching out to catch him, he mentally cursed when the boy wrenched out of his grip, careening into Tom's own cauldron and knocking over its entire contents.

Luckily Slughorn had already seen his exemplary work, and so he would likely receive full credit for the class, but he watched in mild horror as the contents spilled all over Potter. The boy's eyes widened in shock, and then his features went lax.

"Oh dear, oh dear, you really should be more careful, Mister Potter," Slughorn fretted, rushing back over while the rest of the students gawked. "What a shame, it was as brilliant a creation as always, Tom. I'll still give you full credit, of course..."

Potter didn't so much as glance at the professor, his eyes completely glued on Tom, his lips parted in a slight gape. Tom watched him warily, before his eyes flickered over to the professor and back.

"You have nice eyes," Potter said suddenly, still gazing at him intently. "They're so much nicer when they're not red."

Tom blinked at the unfathomable statement, which received a few giggles and whispers at Potter's abruptly obvious predicament, accompanied by a softer murmur wondering what glamours he might have seen Tom use. They thought he'd look mysterious with red eyes; he scoffed. He'd never magicked his eyes red, but he almost preferred those whispers to the ones that speculated whether or not Potter had seen him cry.

He felt his rage building, a simmering, wrathful hate that built the more he considered the implications of Potter's mistake.

"Oh dear," Slughorn said again worriedly, catching up with the situation and wringing his hands, before continuing reassuringly. "I suppose I'll have to make the antidote. It'll take a few hours..."

"I'm afraid, Professor," Tom spoke reluctantly and with a sense of dread. For once his own genius had not worked to his advantage. "That I replaced the betony with olibanum, to strengthen the solution. You see, I didn't think it would actually be used, sir, so I saw no harm in it, but-"

"It would react terribly with the asphodel in the antidote," Slughorn concluded in defeat, deflating. He frowned at Potter with consideration. "With those side-effects, it might be kinder to let the potion wear off on its own."

"I do apologize, Professor, I never thought-" Tom added hastily, inflicting his voice with proper regret. Internally he cursed Potter's stupidity and inability to control himself due to his imbecilic, lustful, petty desires.

"No, no, Tom, it was a brilliant alteration, I just don't think the headmaster would appreciate it if I tried out new antidotes on a student when the love potion itself is relatively harmless..."

"I don't mind, as long as I can stay with Tom," Potter spoke up suddenly.

Tom resisted the urge to scowl, because he did not want to endure his company for an entire week. Slipping away to the Chamber, exploring the school, and practicing his dark magic all required privacy. If the boy clung to him, he couldn't even study for the creation of his horcrux.

Before the boy had disrupted his plans, he'd believed he could create his first horcrux by the end of the year, using the death of the mudblood that he'd killed with the basilisk, or perhaps the murder of his father and grandparents. He still deliberated which had more meaning; his first kill, or the death of his good-for-nothing muggle relatives. Perhaps the girl would be better, since he thought his father should only wish to be used for such a noble cause as his immortality.

Dismissing the boy remained an impracticality, however, what with all of the witnesses in the room. He had an image to maintain. His classmates, or at least the Ravenclaws, expected him to treat Potter with patience and compassion. Slughorn expected the same.

"It's all right, Professor," Tom said soothingly. "I was the one who startled him, after all. I'll make sure he doesn't embarrass himself too terribly. This way he can even attend classes."

"Of course," Slughorn exclaimed happily. "I should have known you'd handle the situation so well. I suppose if it had to happen to anybody, Mr. Potter was lucky that he spilled your potion and not anyone else's. You'll take good care of him, and I can rest easy," Slughorn leaned in with a conspiratorial wink. "Knowing that you'd never take advantage of the poor boy. I'm sure it'll be a fantastic story to tell, after which we can all have a good laugh."

Slughorn shook his head at that, waddling back to the front of the room with a chuckle. The other students finished packing up their bags, running off to gossip about the excitement, and Tom clenched his teeth.

"Can I carry your bag for you, Tom?" Potter broke through his thoughts, and Tom turned to see green eyes looking up at him hopefully through the rims of those ridiculous glasses.

"I can manage, thank you, Potter," Tom said stiffly, the venom in his voice nearly undetectable. The boy certainly didn't notice. They finished packing their supplies, and Tom slung his bag over his shoulder with a bit too much force. Turning around and taking a few long strides, he didn't wait before heading out of the room, but Potter followed quickly on his heels.

Silence, and then-

"Can we have lunch together, Tom?"

I ship these two so hard it's not even funny...but I have no confidence whatsoever writing the pairing myself. Any feedback you might have would be considered immensely helpful! ^.^;