Title: A Little Bit Of Fun

Summary: Harry didn't know how he got to be in the past, sitting next to a teenage Tom Riddle, but damn it if he wasn't going to get revenge. No matter how petty he has to be.

.

Tom Riddle really was a genius.

It's unfortunate, because things would be so much easier if the other male was, say, another Crabbe. Harry slid a glance to his table partner and tried to imagine Riddle as stupid, but his mind was not co-operating.

Riddle glanced over and raised an eyebrow. Harry blinked and kept staring, not at all ashamed at being caught, because this teenager was a criminal. Riddle held the stare for a moment, then must have realised he was actually participating in a staring contest, because he frowned and turned away.

At the front of the class, Dumbledore demonstrated once again how to transfigure between materials as well as forms, whilst also changing the mass. Usually when people tried to transfigure different materials and sizes, the new shape would automatically warp to compensate for the lighter or heavier density.

Too bad Hermione wasn't here to show her amazing knowledge, because that would put the egotistical twat in his place. Said heir of Slytherin sat there beside Harry, a transfigured swarm of glass bees in front of him, and a smug expression on his face.

Harry wanted to kick him, but instead changed his brick into a replica of a wooden grim growling at a plastic werewolf in a forest of cotton-candy under a chalk moon.

"Wow." A girl sitting on the other side of the isle leaned over and gave Harry a pretty smile. "That's really nice. I can only manage this." She gestured at her cat sheepishly.

"Only?" Harry scoffed. "Look at how detailed yours is – it's practically alive!"

The girl smirked and pointed at the floor where a brick sat. "It is alive." She pulled back to sit properly in her seat and petted the sleeping cat on her desk.

Harry reassessed his image of the Hufflepuffs in this time, and made a mental note to stay away from that girl. He refocused back on his desk, only to find that Riddle got curious from the girl's comment and turned to see Harry's work.

Harry gave Riddle an innocent look, but there was challenge in his eyes. Riddle tilted his head and turned away to his bee's. Harry turned away as well, pouting, but soon a few 'ahh's went up.

Harry looked over to find a large gorgon made of snake skin and clay sitting in front of Riddle. Harry bounced slightly and muttered the spell for a plastic griffin, shaping it with his magic to have the creature rearing up, claws outstretched.

Riddle narrowed his eyes and Harry smirked, leaning closer to whisper, "You can do better than that."

And they were off.

The whole class had gone silent by the time Harry got annoyed. Tom Riddle was good, no mistaking that, but Harry was going to win this. Harry jabbed his wand angrily and sent the model solar system Riddle had made out of pink diamonds into the wall, along with Harry's own clay mother dragon breathing fire and protecting her golden eggs.

Riddle, along with most of the class, flinched as the sculptures broke, and turned towards it automatically. The shards swarmed and rose up in the shape of paper aeroplanes, dive bombing Riddle in a great show of combined charms.

By the time Riddle cut them apart with a slightly too vicious indigo spell and turned back to Harry, it had been only a few seconds. However, in that time frame Harry had hopped up from where he was still sitting in his chair and transfigured the table into a floor to ceiling pillar.

It was detailed with everyone in the class lazing about in the sun or running around. The fake people all turn towards Riddle when he glared at it and they stick out their tongues in childish insult. Harry just leaned cockily against the pillar, smirking at Riddle's irritated expression.

Riddle stood and twisted his wand, slashing it at the pole. The stools they had been sitting on shook out their legs for show and sprinted at the pillar. The whole thing shattered on impact like glass and forced Harry to dive to the side, while Dumbledore threw up a strong shield over the students.

The pieces paused mid-air and pulled together again into the exact same pillar, as if Riddle had just turned back time. He then melted down the pole and converted it into a river of lava along the floor of the class room.

Harry scrambled up from where he had thrown himself down to avoid the shrapnel, and backed away from the very hot liquid. It cooled when Riddle hit the edges with augumenti. The end product looked like the river Styx, the lava rising up and looking like tormented souls.

The battle continued on in that vein, getting more and more elaborate, detailed, and very good if Dumbledore's grin and twinkling eyes was any indication.

Harry incorporated charms, simple pranks from Fred and George, and other magics like household charms and tricks that most parents used on their children so they stayed entertained. Riddle, using charms like Harry, also had more obscure magics in his works.

The Slytherin played dirty, not that Harry had expected him to fight fair in the first place. He flicked his wand at Harry when it was the time traveler's 'turn' -because there was only one giant structure and neither would settle for anything smaller- and Harry was encased in a bubble of water.

Harry glared with his arms crossed, not even bothering to summon a bubble head charm as he waited impatiently to be acknowledged. Riddle turned to Harry, a smug look on his face, and his mouth twitched into a smile at the sight Harry made.

Harry finally muttered something, bubbles streaming out of his mouth and his words incomprehensible, but still the ground rose up on his command. The floor surrounded Riddle in a cage while the water around Harry splashed to the ground then slid up to join the main transfigured structure.

Harry swished his wand around, stalking around the once-table and melding it into a floating ball of what looked like dark blue water. If you squinted you could see fish and sharks as well as whales, even a few boats.

Riddle broke out of his cage by bending the bars down and started to make his own transfigured structure with the now broken jail cell. Harry paused in his shaping, casted a tiny shield that encompassed Riddle's wand, then continued with his masterpiece by adding land, clouds and soon buildings.

Riddle, pissed and not able to use magic because he was wary of what would happen with the shield, slid up to the hovering ball of water and shoved his hand through it, snatching Harry's wand and throwing it over his shoulder towards the door.

Harry looked horrified and a strangled sound emerged from his throat as he quickly ran for his wand. Riddle immediately changed the main structure again into what looked like a giant and very realistic panther.

Harry grabbed his wand with a particularly annoyed expression and flicked it at Riddle, who went tumbling to the wall. Even though the shocked face Riddle made caused Harry to snicker, the young Dark Lord managed to land on his feet so he was horizontal to the floor. Riddle had his gravity changed and did not look happy about it.

Riddle mumbled to himself, calculations and options speeding through his mind, and rearranged himself back to normal just in time to destroy Harry's rather elaborate wooden-but-transparent creation of Hogwarts.

The first years had been coming in boats, other students and teachers were in the great hall already, and even ghosts were floating around. If anyone had looked closely they would have seen the irregularities; different teachers, students that might have been distantly related to the ones now, and Dumbledore in the Headmaster's chair.

This continued, distracting each other with tricks, cages and Harry turning Riddle's hair rainbow coloured. Riddle grabbed another table from behind them to trap Harry in but that added to the competition by allowing both of them to spell the items instead of one at time.

The designs were amazing. Harry added lights and sounds to his and Riddle included emotions, amazingly enough. At one point Harry just stood, blinking incredulously at the small Forbidden Forest Tom had made with the feeling of fear and panic emitting from it.

When the class finished, no one bothered to move, not wanting to miss a moment. Either way, it ended in just a few more minutes. Riddle commanded a huge adder with its head reared up, hissing and spitting. Harry's hydra screeched, baring three-heads-worth of deadly, sharp teeth.

Both creatures clashed together, their claws and teeth tearing each other apart until nothing but scraps of both remained, and the two boys were left standing there and panting from so much use of such complicated magic.

They walked purposefully towards each other and Dumbledore raised his wand in preparation to drag them both apart if necessary. They stopped inches apart, sneering and glaring. Harry's lips twitched and as one they burst into laughter, Riddle throwing his head back and Harry bending over, hands on his knees just so he didn't fall over.

When they both calmed down they congratulated each other.

"The thestrals you made were amazing." Harry conceded. "I can't believe you made a basilisk, though," he added with a mutter, glancing away. When it had popped up he nearly had a heart attack and second year flashed through his mind.

"You recognise it?" Riddle raised an eyebrow in curiosity. "Most aren't taught about it as they're believed to be almost extinct."

"..."

"And you created a rooster, complete with crowing and everything," Riddle hummed.

Squaring his shoulders, Harry smiled falsely. "Your inferi were creepy." Yeah, that's right you arse of a dark wizard, I'm on to you.

"Your flaming werewolves were ripping them apart, if I recall correctly," Riddle shot back.

"... Maybe you're just tired. Seeing things."

"You changed my gravity, which was fascinating," Riddle allowed, seeing that Harry was retreating.

"You changed it back just as fast and then stuck me to the ceiling," Harry grumbled.

"I did, didn't I?" Riddle said in smug satisfaction.

Harry laughed. "Again in charms?"

"It's a date," Riddle purred.

The 'war' continued for around three weeks before Dippet asked for Harry to go to the Headmaster's office. They had found a way back.

Tom woke up to a note on his pillow. Kind of bemused that anyone would have left him a note -or was able to reach his bed in the first place after having gotten past the traps- he skimmed it. It was short and to the point, plainly stating that Harry had fun but was leaving...

What?

Tom ripped the bed curtains open and saw all of Harry's things were gone, even the extra bed that had been fitted in. "Micky!" Tom called for a house elf he discovered a while back as he put on proper clothes.

A house-elf appeared, as commanded. "What can-?"

"Where is the student Harry Miller?" Tom interrupted with a smile. "I think he left a picture of his family here and I wish to take it to him personally."

The creature looked indecisive for a moment but it spoke up soon enough. "Sir Harry is in Master Dippet's office, Sir."

Tom reached the gargoyle in record time, snapping out the password. Thankfully, he was a Prefect and didn't have to waste time guessing. He opened the door just in time to see Harry vanish.

"Mr. Riddle, was there anything you wanted?" Dippet questioned.

A slow smile spread across Tom's face. "Yes. But don't worry, I have it all planned out. I will get it back eventually."

A month later, Harry found an emerald turtle sitting on the end of his bed when he came back from classes. The likeness to one of Tom's transfigured animals was just coincidental.

It had to be, because Dumbledore said everyone would forget. Right?