"Well that was rude." Harry muttered as they left, elaborating the e in a very childish way. Tom chuckled at him and jerked the body left, to which Harry jerked it right.
They did this several times. Some people gave them odd looks and there may have been a few flashes as the Boy-Who-Died-Way-Too-Many-Fucking-Times casually strolled through the alley.
Just then, Tom caught sight of a furious looking Albus Dumbledore coming at them and quickly tugged control of the body hard enough to knock Harry back into his head. "Aha!" Tom cheered and dashed away.
'Why are we running, my lord?' Harry asked and Voldemort nearly tripped and fell over.
"Why did you call me that?" He asked in exasperation.
'Well, you are a dark lord, are you not?' Harry asked innocently. 'By the way, what is a dark lord?'
Tom grumbled and was about to explain. Suddenly though he remembered that they had so ceremoniously murdered the Dursleys. He remembered lying to the social workers, then being choked out by his cousin. Then he remembered waking up again and dying once more. Then-
'Why are we remembering all this now' Harry asked and that snapped Tom out of his trance. His face was pale and he was about to explain when he jerked Harry's body down to miss a red light that nearly smacked him in the face.
'Oh! Are we being attacked?' Harry asked gleefully. 'I guess I can try out that spell you mentioned while you thought I was sleeping.'
Tom again barely had time to ask what the hell Harry had meant before Harry brandished the other wand with his left hand and yelled "Fiendfyre!" and suddenly the world got very hot.
Dumbledore, who was walking very calmly over to the clearly insane boy stopped as soon as Harry had brandished his wand and barely had time to duck when a fire basilisk sprouted from thin air to chomp at his beard.
"You idiot!" Tom roared, but Harry didn't care at all. Too caught up in the pretty colors. Not his words of course, just what the foolish boy had been mumbling since casting the spell.
He caught sight of Dumbledore fleeing and shot a killing curse at him, but of course missed.
"How the fuck did he know where we were or what we had been doing?" Tom ranted, not at all paying attention to the flames that were clearly getting out of hand. "What the fuck business is it of his anyway?"
In his rage, Tom decided to try out some interesting spells he had learned in East Asia. If they were going to die in this inferno anyways, then they should at least get some fun out of it!
"Dìyù de yěshòu, wǒ zhàohuàn nǐ! Voldemort shouted while stepping out of the alley. A loud screech was heard throughout Diagon, then a vertical tear streaked down the middle of the street, before opening. Several beasts poured through. They were as large as tigers and had large gaping maws which were chomping rapidly. Voldemort orchestrated them to go attack the fleeing wizards, then took control of the Fiendfyre with ease.
Tom/Harry strolled calmly through the Alley. Tom sent a killing curse at a witch who was standing around, too frightened to move. Harry wanted to kill things too, so Tom gave him a few spells to try and he waved the Potter wand at a Red-headed man which decapitated him. Harry laughed maniacally.
They kept walking as the fire busted through shop after shop, destroying everything in its path. A family of four were reduced to ash in a mere moment. A little boy tripped and Harry slashed him in half. Tom was holding an old man under some kind of torture curse that made Harry feel like he was experiencing the finest pleasures in the world!
Tom shouted out a yellow hex that made someone's eyeballs explode and his blood squirt out everywhere. A woman carrying her baby was send flying back by Harry. He stomped over to them and shot a curse which caused the infants head to grow very large before popping. The woman screamed, but was decapitated by Tom.
One of the large beasts that Tom summoned crashed through the glass and started eating one person who thought they could sneak up on him.
They were both laughing now. Nobody was safe from their destruction. The fiendfyre roared which send shivers down Harry's spine. Tom seemed to have it under control though.
By then Dumbledore had made it through the mobs of people and stood several yards from the Dark Lord.
"Hello Harry, or should I say Tom?" He greeted with unnerving calmness, gazing at Harry's scar and grimacing.
"Hiya whoever the fuck you are!" Harry greeted. Tom didn't quite notice, too busy keeping the cursed flames from burning them.
"Harry?" Dumbledore choked. An odd look coming over his face. Harry was even more confused now.
"That's what people seem to keep calling me." He answered and Dumbledore spoke once more.
"Harry, my boy. Could you let me in?" He spoke in a calm, innocent voice.
"Yeah, whatever." Harry said, not knowing or caring what the stupid old man meant.
Dumbledore bowed before resuming his previous legilimency attack. Harry wavered, and Tom cried out. "You fool! Where's your self-preservation?" He asked, already knowing it had gone down the drain when his limbs were being gnawed on by dogs.
After several moments, Dumbledore came out looking pale. He just stopped and stared, surveying the carnage around him. The sadness he felt was clear on his face.
"Just as I had surmised. I suppose the only good part of all this is that it won't matter after you've died. All this death will be as if it had never occurred. Still, it saddens me greatly that it had to come to this at all. Harry, my boy, I wish I could save you. But alas, I fear the only way to end this is to kill you."
Harry stumbled back, now terrified. "No! Please don't. Please!"
Dumbledore looked like he would change his mind briefly, but hardened his features.
"I am very sorry, Harry. But I simply cannot allow Tom to live again. Even if it means hurting you, I must for the greater good." He finished before incanting something. No. Incanting wouldn't be the right word. It was a song. It was very loud too, he noticed.
After several moments it got louder, too loud! Tom/Harry screamed and fell to the floor. Dumbledore was swirling his wand in a circle and singing. Everything had begun to shine a bright white and Dumbledore became a blur. His form was a silhouette amongst blindingly white surroundings and the noise had become deafening.
Their wails were tuned out by the singing. As Dumbledore sang, he became distant. Harry and Tom were flying away, though they did not feel any wind. All Harry could think of was the light from the priest. How bright it was. How it could swallow the world. It had to be contained. It needed to be contained. It was unnatural.
'Let me in' The voice said and Harry shook his head. He did not want to let this horrible thing into his head. Tom was catatonic. He lay crouched in a corner of their split mind muttering something. 'What kind of sorcery is this?'
Harry felt himself falling.
The chocolate had felt odd on his tongue. "Of course it feels odd." Tom had been saying. Fortescue's ice cream isn't like any of that muggle crap you get.
After meeting Lucius, Tom had insisted on getting some ice cream. He loved having a wand of his own, but having ice cream was just something that was even better. The first time Tom had visited Diagon Alley, the first place Tom had visited was Fortescue's.
The place had been owned by Florean's mother then. She hadn't looked at him like the dirty orphaned Tom Riddle he was, instead handing him some ice cream and smiling at him.
Tom Riddle had never known love, but he had been a boy then. He had desired kindness and friendship. He did not know of blood statuses or silly school rivalries. He had just been a lonely boy who was just introduced to a world that he never had in the orphanage. Then he had been shown kindness by a stranger. That had created a hope in him that lasted a good several months, soon to be crushed by the bigotries of Wizarding Britain.
He would never become a feared and respected wizard by accepting kindness and wishing for silly things like friendship or love. However, despite all of his manic ideas and murderous adventures, Tom had never forgotten that first ice cream at Fortescue's. He thought that Harry should experience that too.
He had been furious of course, after putting together the pieces that were not so easy to find post-war as Harry's horcrux. Little conversations he remembered Harry hearing as wizards thanked him on the streets. Several thoughts he had plucked from said wizards and witches as they passed. Completely unaware of the malignant resident in Harry's famous scar.
He had imagined the boy being tortured in several gruesome ways, but when it had come down to it, Tom didn't feel anything at all. Maybe it was because he was also experiencing it, but seeing that innocent boy squirm under the pain that fate had brought him didn't make him happy at all. In fact, after getting to know the boy, he had just seen himself being tortured. Little orphan Tom Riddle. Alone in the world. Failed by Albus Dumbledore. Halfblooded. Timid. There wasn't anything to be gained by torturing him.
After realizing that, Tom had done some soul searching. He didn't notice anything else amiss though. He still hated muggles. He still desired to be known and feared. He still enjoyed the feeling of crushing somebody's skull with a curse. Nothing substantial had changed in him. But when he thought of Harry, he only felt fondness.
Was this the product of being forced to share a mind with him? When his horcrux degenerated and finally crumbled, did his personality morph to see it's host as something to protect?
Tom would never know. If he were given an answer that sounded too much like Dumbledore's drivel, he'd probably need to torture a muggle until his brain snapped in order to purge the thoughts. He was an insane psychopathic Dark Lord after-all. An insane Dark Lord who had on several occasions happily answered Harry's stupid, inane questions instead of crucioing him like he had done to several servants.
This was his life now. Why did he make a horcrux again? His musings were cut short when he noticed that his mouth was covered in ice cream and he hadn't remembered eating any of it. He of course, in typical dark lord fashion had completely spaced while monologuing in his head and his body had done things that he in no way recalled.
'I didn't even get to taste the core.' Tom moaned and Harry giggled.
"I actually ate two cones while you were playing scary dark lord in my head.' He admitted happily. Tom scowled while Harry laughed and then they got up. But nobody was in the alley anymore. It had gone deathly quiet. Tom looked around; the once cheerful environment now radiated malice.
Harry was quiet too. In fact Tom didn't feel him at all which was worrying. "Harry?" He called, but got no answer.
He looked around, but stopped when he saw his reflection. He was still in Harry's small body, but his face was blanked out. He stepped closer and he saw his face stare back at him. Only it wasn't the face of little orphan Tom Riddle. It was the face of the creature he had become after too many rituals. Voldemort stared back at him in a grotesque mockery of a smile.
"Let me in." The voice said with his lips. He took several steps back, but the creature in the reflection followed him after stepping out of the glass.
"LET ME IN!" The voice suddenly roared and Tom collapsed, covering his ears.
That's how Vernon and Petunia found Harry. Laying on his bed, shaking violently as several seizures took him. His eyes were black and his mouth was open. An impossibly bright light coming from it. Petunia was pale and her husband didn't look much better.
He stopped then. Dead.