Becoming Professor Moriarty's Probability

Going back in time slightly, to a few days after the professor had given birth,

- Knock, knock, knock...

Rachel Watson, her once-bright and lively demeanour now nowhere to be found, stood at the door of the familiar boarding house, her face gaunt and worn.

“Holmes? You’re in there, aren’t you?”

- Knock, knock, knock, knock...

“I know you’re in there, so open the door already. Mrs Hudson couldn’t stand it any longer and called for me!”

Her voice, unusually dark and forceful, echoed as she raised it, but there was no response no matter what she did.

“Hey! Holmes!”

“........”

“I’m sorry I didn’t come sooner! I’ve been struggling too! But ignoring me like this...”

Feeling a pang of betrayal, Watson gripped the doorknob tightly and gave it a harsh tug.

- Creeeak...

“... What?”

She blinked, taken aback as the door creaked open, having been unlocked all along.

“.......”

But her surprise was short-lived. She stepped into the room cautiously, her expression tense.

“... Ugh? Kullu, kulluk!”

However, her cautious approach proved futile as she immediately wrinkled her nose and covered her mouth, coughing heavily.

“Ugh... what the hell...”

The room was filled with a choking haze of smoke that stung her eyes and nose.

“What on earth is this smoke...!”

Watson, visibly distressed, coughed uncontrollably for a moment before staggering forward, her hand still pressed against her mouth.

“... Huh?”

And then she stopped, her breath caught in her throat, as her gaze fell upon the wall obscured by smoke.

“What... happened here...”

The wall, plastered with countless photos of Professor Moriarty, was riddled with bullet holes.

Not only that, the floor was littered with torn fragments of the professor’s photographs, scattered everywhere.

The only photo left intact among the chaos was one depicting the professor holding two children— a pair who seemed vaguely familiar, almost hauntingly so.

“Ad... ler?”

“... Huh?”

Watson, staring at the unmarked photo as if entranced, was startled by a faint, trembling voice from beside her. The sound caused her to whip her head towards it in alarm.

“........!”

And moments later, with wide eyes, she froze in place, utterly stunned by what she saw.

“Adler... is that really you?”

“Holmes!!”

Charlotte, slumped in the armchair beside her, looked utterly destroyed— so far gone that she was almost unrecognisable from the vibrant girl from a year ago. Her expression was far more haggard and desolate than Watson’s. She was the picture-perfect definition of a shadow of the person that she once was.

Her arms, exposed through the loose folds of her bathrobe, were riddled with needle marks. Even at that moment, she had a pipe of strong opium between her lips.

And on the desk beside her, a golden mana stone burned like incense, filling the room with its acrid presence. It wasn’t hard to see how she’d descended to such a state.

“Are you insane!? Have you finally lost your damn mind!?”

Watson, panicked, grabbed Charlotte by the shoulders and shook her violently.

“Adler... hehe...”

“Do you not see what you look like right now? If you keep this up, you’ll die! Is that what you want!?”

“... You’ve finally come back, haven’t you?”

Yet Charlotte, her eyes unfocused, simply gazed at Watson with a hazy, delirious smile, mumbling incoherently in a voice that sounded more foolish than anything else.

“Do you... have any idea... how much I missed you...?”

“Holmes.”

“Every single night, I cried because I wanted to see you... Then I’d fall asleep from sheer exhaustion... over and over again...”

Watson stopped scolding her, instead staring at her in silence, her face stricken with disbelief and sorrow.

“Adler... but, I... I have one question...”

Still grinning like a fool, mistaking Watson for Adler, Charlotte pulled her into a desperate, trembling embrace and continued in a broken voice.

“You won’t disappear again... right?”

“........”

“Please... I’ll do better this time... I don’t even care if you stick around other women, just...”

Unbidden, tears began to drop steadily from her eyes.

“Promise me you won’t ever leave my side again...”

Her tears fell upon the photograph she clutched tightly, despite her distress.

“Please... it’s my last wish...”

“........”

“Adleeeer...”

It was the ‘photograph of Adler, a treasured possession from the Bohemian Queen’s scandal, received instead of payment, that she still held dear.

“Don’t leave meee...”

“.......”

Watson, watching the pitiful sight before her, couldn’t hold back the anguish in her expression. Closing her eyes tightly, she silently wrapped her arms around Charlotte, pulling her into a firm embrace.

“... He really was the greatest asshole.”

Even in Watson’s own eyes, tears welled up— her golden irises, now dulled and murky, glistening with unspoken grief.

.

.

.

.

.

A few days later, in the upscale residential area of London, where the weather had remained perpetually gloomy for an entire year.

- Step, step...

For the first time in nearly a year, Charlotte stepped out of the boarding house, staggering as Watson supported her on their way to a particular mansion in the area.

“... So, Holmes. Why did you insist on coming here the moment you woke up?”

“........”

“You still need to recover. If we’d waited any longer, you might have—“

“... We’re here.”

Though Watson’s dedicated care over the past few days had improved her condition somewhat, Charlotte still lacked the strength to even lift her hand and knock on the door.

“Knock for me, please, Watson.”

“... Haah.”

At her emotionless request, Watson sighed but begrudgingly raised her hand to knock on the door in her stead.

“”.........””

Yet, no response came from beyond the door.

- Creak...

“Is leaving doors unlocked the latest trend in London these days?”

Watson, as a precaution, turned the doorknob, only to find the door opening far too easily. She walked in with a slightly incredulous expression.

“... So, where exactly have we come?” 𝓯𝙧𝙚𝒆𝙬𝙚𝒃𝙣𝙤𝒗𝓮𝓵.𝙘𝙤𝙢

“Sister. I’ve come out.”

Charlotte, ignoring the question, spoke in a low voice instead.

“You thought changing your address would stop me from finding you, didn’t you?”

“........”

“Don’t worry, I’m not here to reprimand you. I just have something to ask...”

Muttering to herself, Charlotte began opening doors one by one as she ventured deeper into the mansion. Abruptly, her words stopped as she froze in place.

“Oh my god...”

Curious, Watson peeked through the slightly ajar door Charlotte had opened, only to find herself equally paralysed by what she saw.

“.......”

Sitting silently on the edge of the bed was Mycrony Holmes, her expression even more void of emotion than it had been in the past. Her body bore scars from cuts across every part that could reach— arms, hands, everywhere.

At her feet lay nearly lethal doses of morphine syringes and bottles of strong alcohol, scattered carelessly across the floor.

- Swish...

“... Hey!”

When Mycrony wordlessly brought a knife in her hand to her own arm, Watson darted forward and grabbed her wrist in panic.

“Are you out of your mind?! Do you want to bleed out and die?!”

“... You’ve come.”

Only then did Mycrony slowly lift her head, her lifeless eyes focusing on the sibling standing in front of her.

“Have you come to hold me accountable?”

“... Accountable for what?”

When Mycrony’s trembling voice posed the question, Charlotte silently shook her head. The older Holmes sibling blinked in confusion, her expression going blank for an instant.

“... Adler gave me the medicine.”

Lowering her head once more, Mycrony began muttering softly.

“The one and only cure— the panacea... He gave it to me, instead of taking it for himself.”

“........”

“In his will, he said as much. That it would be better for London if I survived instead of him.”

Hearing those words, Charlotte clenched her fists so tightly that her knuckles turned white, cutting off the flow of blood.

“It was the first time my calculations went wrong. I thought his only goal was to toy with me...”

“........”

“So I... I had no choice. I didn’t know things would turn out that way... I didn’t mean for it to happen...”

Mycrony’s voice wavered as she offered incoherent excuses, her complexion pale as she faced Charlotte, who remained silent, her expression unreadable.

“... Did you know?”

After a brief pause, Mycrony let out a deep, shaky sigh and glanced sideways at her sibling before beginning to speak.

“That medicine... it freed me from the curse of numbness that had plagued me my entire life.”

“........”

“But... even after finally feeling the sensations I had wished for all my life...”

From her eyes, the same liquid that had fallen from Charlotte’s and Watson’s eyes a few days prior began to stream down.

“... Nothing satisfies me anymore.”

That same dull, golden hue, now tainted, glistened in the tears rolling down her cheeks.

“Even injecting myself with morphine until I reach lethal doses, even drinking until my brain feels like it’s melting... even carving my own flesh with a blade...”

“.......”

“... It only helps me forget, for the briefest of moments, the endless despair and helplessness I feel every second of my life.”

Unlike the professor, who could force herself to cry, Mycrony’s tears were something she had never shed in her entire life until now.

“Do you... know why?”

Her voice trembled as she choked out the question, her tear-streaked face turning toward Charlotte. However, Charlotte could only avert her gaze in silence.

“... I have something to ask.”

Breaking the heavy silence, Charlotte’s quiet voice sliced through the tension.

“Adler... is he—“

“He’s nowhere in this world.”

Before Charlotte could finish her sentence, Mycrony’s voice, once again void of emotion, cut her off.

“Whenever I regained some semblance of clarity, I used my abilities to search the entire world over and over again... but I gave that up not long ago.”

“”........””

“He’s no longer in this world.”

At those words, Charlotte closed her eyes, her face unreadable.

“... Let’s go.”

“Charlotte? But your sister—“

“There’s a place we need to go before it’s too late.”

Without another word, Charlotte turned on her heel and began making her way out of the mansion.

“Where are we going now...?”

“To the study.”

“... What?”

Watson, her expression stunned, glanced between Mycrony and Charlotte before reluctantly following the latter.

“... If only I had just let you kill me that day.”

- Swish...

“If only... I had claimed you as mine from the very beginning...”

As Charlotte’s fading figure disappeared from view, Mycrony stood frozen, staring after her for a long while. Then, her eyes, once again devoid of light, turned down to the knife in her hand, which she picked up once more.

“Would everything have gone differently?”