The Closet of Possibility
by Books of Change

Summary: Harry Potter accidentally turns 221B's cleaning supply closet into a magical portal that leads to worlds that reflect the deepest, most desperate curiosity of a person. Sherlock, unfortunately, didn't know that when he opened it to take out the vacuum cleaner. Sherlock, HP, Canon Sherlock Holmes triple crossover; ASIM compliant

Warning/Additional Notes: This story is based on another story I wrote: A Study In Magic. All you need to know is that Harry Potter was adopted by Sherlock and John when he was nine (and they had another kid when Harry was thirteen). The HP timeline was moved up and Sherlock timeline was moved back to make this work.

From the notes of J. H. Watson, MD
Late of the Indian Army

It is years since the incidents of which I speak took place, and yet it is with diffidence that I allude to them. No amount of discretion and reticence would allow me to make the facts public without risking accusations of insanity or worse. But now, with due suppression of details and light-heartedness of narrative, the story may be told in such a fashion as to entertain and enlighten. The reader will excuse me if I conceal dates or any other fact by which he or she might construct timelines.

We were having a quiet evening in our rooms when the incident happened, as a tempestuous gale battered the twin windows of our lodgings. Holmes was enjoying his evening pipe and a pamphlet on medieval music, and I was deep in a recent treatise upon surgery. Amidst the muffled sounds of the sobbing and moaning winds outside, we heard the door to our lumber room open on its own accord. Both Holmes and I glanced at it, and, to our utter astonishment, found a strange man staring incredulously back at us from the opening.

The man was rather over six feet, and had the same thin, rangy, loose-limbed build of Holmes, though not as excessively lean. His eyes were an eerie pale blue-gray, slanted and rather feline in shape, and they possessed a piercing quality that again reminded me of Holmes. The rest of his features were a study in contrasts: A mass of dark curls framed his long pale face, which possessed exotic cheekbones, and the most lavishly accentuated upper lip lent the man an air of effeminacy; but his fine retroussé nose, thick eyebrows, and strong jaw line were absolutely masculine, and gave his whole expression an air of alertness, decision, and determination.

The three of us regarded each other for a full minute, too stunned to speak. Then the stranger, whom I had then just realized was only in his trousers and shirtsleeves with the top two buttons of his shirt undone, muttered something I did not catch, turned heel and closed the door behind him.

Holmes and I immediately sprang to our feet and wrenched open the door to the lumber room. For a few moments, we stared in silent amazement at the familiar sight of ancient newspapers stacked chin high within in the small space, the strange man nowhere in sight.

Dazed, both Holmes and I staggered away and resumed our seats by the fire.

"I can tell from the look on your face that I must quickly discard my hypothesis that we have been exposed to a hallucinogenic substance," said Holmes, breaking the silence. "Two men may hallucinate separately, but they are unlikely to see the same illusion."

"So you saw the man, too."

"As clearly as I see your good self. Yet both his entrance and exit defies human reasoning. Even if there is a secret passageway in our modest abode which has somehow escaped my detection, the man bore no sign of having braved the vile weather outside and appeared as honestly surprised to see us as we ourselves were to see him. There is also no apparent purpose to his brief appearance, except perhaps to shock and astonish. However, our guest seems to have an idea of who might be behind this."

"I'm afraid I did not hear last his words, if that is how you know our stranger has a clue."

"He said, 'damn it, Harry' with the kind of exasperation one who has suffered many such similar incidents may express. One wonders how Master Harry has accomplished this feat when he is but a boy."

"How do you know Harry is a boy?"

"Our unexpected visitor wore a plain gold band on his left ring finger. He is a married man, then, of several years judging from the signs of wear. The inevitable question to follow is the existence of children. Young master Harry has the necessary degree of knowledge and intelligence that allows him to devise the means in which he made a stranger temporarily appear in our lumber room. The stranger's youthful appearance makes the existence of grown children unlikely. Of course, Master Harry may be a relative or older family member, but the creases on our guest's clothes tell us he has been in his shirtsleeves the entire day, had not donned a tie for the same length of time, but no one commented on his deplorable state of extended undress. If we hypothesize Master Harry is the perpetrator of the prank, and the victim is our guest, then Master Harry is a boy, probably our unexpected guest's oldest son, which we can infer from the way he addressed him by his Christian name."

"How extraordinary!" said I. "If your reasoning is true, then young Master Harry's skill must surpass that of the famed escapologist Houdini; even he would find it difficult to replicate what happened here."

"I agree; and as you undoubtedly noticed, there was no sign of preparations and there were no contraptions within our storage space," said Holmes. "It was, in fact, entirely as we have last accessed it, albeit with more dust. Should we ever see our guest I again, I would love to question him how Master Harry did it."

The discussion on the matter ended on that note. I turned to bed shortly afterward, leaving Holmes to brood over our latest perplexing mystery. In the dreamy landscape between slumber and consciousness, I heard a door open and close from the floor below. I assumed it was the sound of Holmes entering his bedroom.

I awoke to a chilly morning. The pale sun roused above the jungle of man-made structures that had been huddling helplessly against the imperious storms of the night before. The windows still bore the remnants of last night's assault of elemental forces, dripping muddy water droplets like blood from a wound. Our landlady had stoked a good fire and laid out our breakfast by the time I came downstairs. Holmes was already seated at the table, smoking his morning pipe.

"Another visitor came last night," said Holmes as he poured the coffee. "It was a young man, no more than eighteen years of age, tall and lean of stature, and a lightning-shaped scar on his forehead. He also wore the most absurd combination of clothes I've ever laid my eyes on: form-fitting blue laborers' trousers on his legs, a grey undershirt and red cardigan on his torso, round spectacles on his face, and black shoes with white rubber soles and laces on his feet. He opened the lumber room door from the inside, peered at me with apprehension rather than surprise, and shut the door behind him before I could reach him. When I opened the lumber room door again, it was exactly as we found it last evening."

"No new additions?"

"None whatsoever."

"Did our new visitor say anything?"

"He said 'oops'; a rather mild self-admonishment considering the magnitude of the circumstances."

I munched on my toast thoughtfully.

"Could it be," I started, "that these series of incidents are—"

I didn't continue, as the lumber room door opened from the inside again and the visitor we saw last evening stuck out his head from the crack. This time, he was wearing a blue dressing gown, black trousers that had very narrow legs, and a shirt that was a deep plum colour. Like the evening before, the top two buttons of his shirt were undone and he lacked a tie and proper waistcoat. He also glowered at us with frank annoyance before turning to the unseen space behind him.

"Harry!" the man called out in a rumbling baritone, "It's still doing it!"

Holmes leaped out of his chair and caught hold of the door before our strange visitor could vanish again. Our visitor tried to fight against his iron grip, but Holmes wrenched the doorknob out of his hand and flung the door completely open. To my utter astonishment, the lumber room revealed nothing but piles of ancient newspapers again.

"How am I supposed to go home now?" our visitor complained. Though a stranded man mysteriously deposited in a stranger's lumber room by means unknown, he didn't look at all alarmed, but merely irritated.

"It would be unwise to let an intruder go free," said Holmes.

"Wrong," said the visitor rudely. "It's clear that—"

He visibly stopped. Our strange visitor exchanged his previous irritation for an introspective look quite alike the one I often found on Holmes's continence when he worked on a baffling case.

"Time and date?" asked the stranger abruptly.

Holmes supplied the information.

"Interesting. And you are?"

"My name is Sherlock Holmes. The gentleman over there is my friend and colleague, Dr. Watson."

Our nameless visitor let out a snort, an involuntary sound of mirth. He directed his piercing eyes at me for a second, and then returned his gaze at Holmes.

"Even more interesting," said he, giving Holmes a crooked, one-sided smile. "My name is Sherlock Holmes. Now, don't be like that; surely you don't think you're the only Holmes to be named Sherlock in the world?"

Holmes thought for a little.

"It appears to me," said Holmes, "that you to know a great deal more about the current situation than I. Would you be so kind as to explain?"

"Explaining is one thing, believing is entirely another," the other Mr. Sherlock Holmes replied. "May I sit?"

"By all means."

The other Mr. Holmes made himself comfortable in the wickered chair. There he surveyed our sitting room, taking in the bear-skinned hearth rug, Holmes's chemistry set and framed portraits like a foreigner who had never seen such things before.

"I will first assert," said the other Mr. Holmes, "that I am a man from a far-off future."

Holmes and I merely nodded. Had we not seen the man vanish and reappear twice in an impossible manner, we would have consigned this claim as a statement of a madman.

"You don't seem very surprised," Mr. Sherlock Holmes from the future remarked.

"You have evidence to prove your claim, I'm sure," Holmes demurred.

"Of course," said the other Mr. Holmes. He reached into his blue dressing gown and pulled out a small, palm-sized device. It was rectangular in shape and had a metal strap running through its sides in the middle like a hoop on a barrel. He pressed the indented button on the bottom of the wider flat surface, and a photograph that retained all of the original subject's colours appeared on the black screen, with a time and date clearly writ on the top in white letters. As we stared, mesmerized, the other Mr. Holmes swiped his thumb across the lower portion of the coloured photograph. To our utter shock, a keypad of numbers beneath four white boxes smoothly rose from the bottom of the screen, with a new message 'Enter Passcode' replacing the time and date.

"What is this witchcraft?" I wondered aloud.

"Not witchcraft, just technology," said the other Mr. Holmes. He swiftly pressed four numbers on the screen with his thumb. Each time he touched a number, a black dot appeared on one of the four white squares. Once all four boxes were filled, the screen changed again and showed a gray screen dotted with water droplets, and several brightly colored squares were neatly arranged in rows, four squares per row, each square uniquely designed and bearing a tiny label in white letters underneath. The other Mr. Holmes tapped the square labeled 'Camera', and the screen changed again to briefly display a gray vortex that opened to reveal another screen, this one replicating whatever that was directly in front of the device.

The other Mr. Holmes raised the device so the back would face us.

"Smile," he said. He then did something that made the device manufacture an odd clicking noise. He lowered the device again and showed us the screen.

I couldn't help but let out a cry of shock when the screen revealed a coloured photograph that captured Holmes' and my stunned expressions. The picture was virtually indistinguishable from reality; it was as though device had frozen that moment in time and kept it within its confines.

The other Mr. Holmes looked at our faces and laughed.

"This is only one function of this device, which is called a smartphone. It can also act as a dark lantern, a hand-held reference library, and a … phonograph machine, I believe you call them. It can also make telephone calls and send text messages. A personal telegraph station and post office as it were, without the inconvenience of actually writing a letter or learning Morse code. Speaking of which…"

He pressed the physical button on the lower part of the device. The screen changed to show the rows of squares in the gray background again. The other Mr. Holmes tapped the green square bearing a white circle that was labeled 'Messages'. The screen showed a long list of names, several grouped in one row. Mr. Holmes selected the list item that bore the names 'Harry Watson, John Watson'. The list screen moved to the left and showed a new screen that had many square boxes with rounded edges, light grey boxes on the left and blue boxes on the right, interspersed with sentences writ in the center that bore a date and time. All the squares bore messages of varying lengths. As I read through them in order, I realized the messages were a typed dialogue that was held between Harry Watson, John Watson, and Sherlock Holmes. All of the blue squares on the right were labeled 'Sherlock Holmes', while the white squares in the left were either labeled 'John Watson' or 'Harry Watson', depending, presumably, on the responder. The last white square on the bottom was from Harry Watson, and the message said: WHERE R U?!

The other Mr. Holmes tapped the long, white bar with half-circles at each end on the bottom part of the screen. The bar rose up and revealed a miniature typewriter keyboard. Mr. Holmes started to type out a message using only his thumbs with a rapidity that bespoke mastery.

My Victorian ancestor namesake's London flat, the other Mr. Holmes typed out. Periodically, a tiny white box bearing blue letters would appear above the word the other Holmes was typing, bearing a word that could possibly be the one he was typing. The other Mr. Holmes tapped the blue oval that had the label 'Send' after he finished typing. The message on the white bar smoothly transformed into a new blue square with rounded edges, diagonally to the lower right to the last white square.

A new white square appeared a few seconds later, bearing a new message from Harry Watson:

r u serious?!

The message exchange proceeded in such a manner, Mr. Holmes typing out messages and Harry Watson—presumably the Harry the other Sherlock Holmes had mentioned—responding almost instantaneously, using deeply colloquial language and acronyms.

Harry Watson:

Y did u want to see the Victorian
ancestor you were named after?

Sherlock Holmes:

Was only thinking of taking out the
vacuum cleaner to hoover the test-tube
shards

Why did you turn the cleaning supply
closet into a time machine portal?

Harry Watson:

Was trying to duplicate the Mirror of
Erised, actually, with added ability to
interact with images. I thought it didn't
work, so put the mirror in the closet

Mirror may have exploded.

Sherlock Holmes:

Next time you have to discard an enchanted
item, obliterate it

Harry Watson:

Fine.

Trying to figure out how to get u back.
ETA unknown. Will txt updates

what does your ancestor look like. Send
photos.

Sherlock Holmes:

[miniature copy of Holmes and my photograph from earlier]

His friend's name is Dr. Watson.

Harry Watson:

OMG OMG what is this I don't even
seriously what is air I can't even
BAHAHAHAHA!

"Step-son?" inquired Holmes after the other Mr. Holmes put away the smartphone.

"Adopted son," Mr. Holmes corrected. "He chose not to take my surname."

"Age?"

Mr. Holmes supplied the information.

"Dear me, and I was thinking young master Harry was twelve at the most," said Holmes.

"You were missing a vital piece of data," said the other Holmes, another wry smile on his lips. "Namely, that I'm from a different century altogether. That would put a huge spanner in your deductions. It is not exactly an inference one can glean and consider under normal circumstances."

"Only a madman would consider it with all due seriousness without prompting," Holmes agreed. "So that's that. I presume you are, for all intents and purposes, stranded until Master Harry figures out how to reopen the portal?"

"Yes. It shouldn't take him that long. He already accessed here once, and he knows how to do it again."

"Excellent," said Holmes, wriggling in his seat. "Now I believe you know what I'd like to do while you wait."

"Ask questions," said the other Holmes, "How could anyone resist?"

-oo000oo-

Final Notes: Not an update to ASIM proper, but nevertheless situated in that universe. Sorry, but the whole studying thing messed up my brain a lot. Having said that, the stuff my brain comes up with scares me sometimes.