"The name is Sherlock Holmes," he introduced himself. "But you may also know me as Regulus Black."

There was a moment of complete silence filled with raised eyebrows from the younger man and an air of hesitation surrounding the other. Finally, one of them spoke.

"Regulus Black? As in, Sirius Black's younger brother?"

Sherlock, or Regulus, rolled his eyes. "How dull, I thought I had made it clear."

"I… but, you died." Lupins said, trying not to sound hollow.

"Who said I died?"

Lupin was lost for words.

"I was only assumed by the general public that I have died in the hands of Voldermort, however, the evidence of my death is not found. Only factors that might lead to my death; not my complete demise."

A dozen thoughts ran through Lupin's head but the first that came to his mind was about his best friend. He rarely talks about his younger brother these days and sometimes Lupin wondered if he truly missed him or not. "Does Sirius know?"

Sherlock fell silent. "No,"

Lupin felt a sudden rush of anger for the pain this man has caused his friend over the years.

"You may call me a coward but I have my reasons. I will explain it to you later, for now the Dursleys should be waking up. We have to apparate, I casted a false memory charm over them so they will think the police has come to take Harry Potter away for a mentality check. I have reckoned Harry has performed a few… magic tricks in this household." Sherlock glanced at the boy still pressed to the wall. "Took me a while to craft the charm, the police response is unknown of when Harry will return. I daresay the Dursley household will be quiet happy of this change, one less mouth to feed, and we, on the other hand, will take Harry to my flat near central London. Harry, get your things, we're leaving."

Sherlock grinned his Chesire smile at his perfect plan. He stopped when he caught Lupin's eyes.

"You're afraid I might lose him while apparating." He said, with a pointed eyebrow.

"Most people, especially young kids under six, cannot stand the process of apparition, so I suggest traveling via the Floo Network." Lupins said. "Also, Harry is currently not licensed to apparate, as you do know the rules of the Wizarding World."

Sherlock put on a stupefied face to mock him. "Ah, right, the rules of the Wizarding World. I'm dead in the Wizarding World so rules don't apply to me."

Lupin sighed. "Come on Harry." Harry remained where he was.

"Harry, he's one of us, you can trust him," Sherlock offered. "Explanations later, we have to get out of here quickly before the Dursleys wake up. I'll have to recreate the Memory Charm again and that will not be brief."

Harry followed silently behind without a word. Sherlock volunteered to carry Harry's suitcase while Lupin got out some floo powder. In minutes, they floo to a small apartment in Central London.

"You own this place?"

"Rented. It's impossible to get a flat in London these days." Sherlock dropped Harry's suitcase and threw his discarded suit-jacket at a nearby reclining chair. "Harry, please help yourself. Bathroom is down the hall and a spare room at the end." He pointed at the direction he was referring.

Harry nodded a word of thanks and quickly hurried down the hall, suitcase thumping by his side.

The two adults watched him go before Sherlock swept into the kitchen, clearing out beakers and preparing to start a new experiment.

"Why are you doing this?"

"I would like to test my new hypothesis on the bruising of th-"

"No, I mean, why are you helping Harry? Taking him to a new home, creating that Memory charm, you've planned this."

Sherlock stopped then looked up at the older wizard standing near him. "Because," he said slowly with a half-smile. "Voldermort is still alive."

Lupin couldn't help but instinctively reach for his wand. "Voldermort died. It was in the news," Lupin defended. "He was no longer to be found, it has been six years since the first sighting."

"Oh?" Sherlock stood up and stared at him, head cocked to one side. "Then why does this, still burn?"

He pushed back his left sleeve and turned the inside of his forearm to him. Engraved on the skin was a black snake coming out of a skull's mouth. "You haven't seen what I saw." He said. "One killing curse cannot kill the Dark Lord, not anymore. I know you've have a wide understanding of the Dark Arts. Now does the word, horcrux, ring any bells?"

Lupin's blood ran cold. "Of course. It's the splitting of the soul."

Sherlock smirked. "Good. Smarter than I reckon you for." He covered the tattoo and walked over to the fridge, looking for something.

Lupin bristled at the man's rudeness. "Then what's this have to do with Harry?"

Sherlock didn't even look up from his rummaging at that question. "Mr. Lupin, I do believe this may be a bit far-fetched however I am mostly right," he drawled. "But I deduce that Harry is one of the many horcruxes Voldermort has used to split his soul. Tea?"

If Lupin was drinking something, he would most definitely spit it at the younger man's face. Too bad Sherlock hadn't offered tea earlier.

"Harry Potter, a horcrux?!"

"Dear God, how bad is your hearing? I reckon even the Little Harry could hear me down the hall."

Lupin shook his head. "Are you listening to yourself, Regulus?" The younger man flinched at his real name. "All of the sudden you show up, not dead, and claiming that Harry Potter is a horcrux? It takes a while for a man to understand your ramblings-"

"These are not ramblings!" Sherlock brushed past the table and stopped in front of Lupin, inches from his face. "I know, what's going on. Voldermort has split his souls, more than once, twice, perhaps even more than five." He whispered. "One is the locket," he paused at that word, "one is his snake, and the other is Harry Potter."

He lowered his voice even more. "It happened as an accident; years of experimentation, murder, and deliberately ripping apart his soul into so many horcruxes it had rendered the remainder of his soul unstable. When his body was destroyed, a small shard of his soul broke apart from the rest and latched unto the only other living being in what remained of the room: Harry Potter himself." He glanced down the hall and Lupin was surprised to see a manic grin plastered on the young wizard's face. "What remained of Voldemort's soul must have escaped from the ruins of the house that same night, which proves of his current existence.

I'll have to test whether my hypothesis is true. If soul shard has truly latched onto Harry's own soul, it should grant him some of the Dark Lord's own powers or perhaps a latent connection to Voldemort's own mind."

"But the only way to kill Voldermort is to destroy all the horcruxes." Lupin said slowly.

Sherlock's face remained devoid of any emotions. "We'll see." He turned away to continue on his experiment. Lupin stood off at the side, digesting all that has happened in the mere one hour.

"Why are you telling me this?"

Sherlock inclined his head towards him. "It would be…. better," his face went through a series of emotions too fast for Lupin to catch, "to have someone on my side with the knowledge of the Wizarding World." He said, choosing his words carefully. "I didn't except you to come, today. However all was too late to change anything. If I apparate, you will hear me and that will cause the entire Wizarding World on a frantic chase to find who has abducted the Boy Who Lived. An event I would rather not go through." He explained quickly as if he was trying to cover up something.

His pocket dinged and Lupin watched in silence as the younger man pulled out a thin piece of metal with a glowing screen. He squinted at the screen before bursting into a flurry action. "Ah, Lestrade texted. Sorry, gotta dash," Sherlock threw his coat on himself. "I play the violin when I'm thinking and sometimes I won't talk for days on end. Would that bother you?"

Lupin frowned. "I'm sorry?"

"Potential flatmates should know the worst about each other." Sherlock smirked. "As I said, it's impossible to get a flat in central London and the rent is close to impossible to pay all by myself. You have the money, I presume?"

He didn't wait for Lupin to answer. "I suggest you start packing. Don't worry about the neighbors, I have set enough wards around the flat to keep people from coming. Mrs. Hudson, our landlady downstairs is a squib. She has a small basement downstairs you could use during the full moon." He smiles at Lupin's reaction.

"Oh, and do take care of Harry Potter for me please." He said. And with one swift motion, he slams the door shut.

This will be taken place in 2006 to clear the confusion. Harry Potter will be born on 1998 so just add 20 years to everything in the Harry Potter world. Sirius Black is caught in 2001. 2009 is where Harry will go to Hogwarts.