Becoming Professor Moriarty's Probability

0% London’s worst libertine. A scoundrel and a piece of trash. Yet, paradoxically, the heartthrob of countless women, the casanova who bewitched all of England.

Isaac Adler— a name that left waves of chaos and scandal in its wake wherever it went, to the point that it became harder to find someone in Europe who didn’t know of him.

So, when such an extraordinary figure suddenly vanished without a trace, it was only natural for London to be thrown into absolute chaos.

Months of large-scale search operations, driven by pressure from Britain’s upper echelons (most of whom happened to be women). Frenzied, purposeless protests from women who, overnight, became pseudo-widows.

Countless sightings of Isaac Adler were reported from various corners of the continent, and even multiple impostors claimed to be him.

The sheer scale of this societal phenomenon, triggered by the disappearance of just one man, eventually led to intervention from the British Royal Family itself— a testament to the magnitude of his absence.

And yet, as they say, time heals all wounds. As time flowed on and on, the madness that had consumed London during its darkest days began to subside.

However.

“Yet another request to find Isaac Adler has come in today.”

Even the passage of time couldn’t stem the flood of such cases to 221B Baker Street, the office of London’s finest detective agency— a haven for those desperate enough to pursue their last sliver of hope.

“Truly comical, isn’t it?”

Yet who could have known?

“This damned mutt, huff... what’s so great about him that people are still tearing themselves apart to find him?”

“Then let me go already...”

“Shut up and swallow the aphrodisiac.”

“At least g-give me a contraceptive...”

“Hah... Shut up.”

“... Sniff.”

That the owner of this very detective agency was one of the culprits behind Adler’s disappearance.

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“Stop... please stop... I’m going to die...”

“... Haa.”

Charlotte, who had been quietly glancing at Adler sobbing into his sleeve on the bed, adjusted her clothes and exhaled a puff of cigarette smoke by the window.

“Begging like that won’t work.”

“Sniff, sniff...”

“This is the most secluded place in all of London. Even worse for you, this is an abandoned house in the middle of private property.”

As she said, the place Adler was confined in appeared from the outside to be a derelict, uninhabitable ruin.

Of course, thanks to Professor Moriarty’s spatial expansion magic and layered security spells, the interior was transformed into one of the most comfortable sanctuaries in all of London— a haven hidden amidst its otherworldly chaos.

“Just in case you’re still clinging to hope, let me make it clear. I’ve already cleaned up the ownership papers and resolved all tax issues regarding this property. Legally speaking, there won’t be any legal problems for at least a hundred years.”

“.....!”

“Haha. I used to always tell Watson back in the day— if I were a criminal, I’d be the best in the world.”

“........”

“Technically, keeping you here isn’t even a crime since it’s a form of global justice. But it does feel gratifying to prove my point like this.”

For Adler, whose lifeblood was freedom and the company of women, this place was not heaven but a living hell.

“Well then, it looks like break time’s over.”

“Eeek.”

“I’ll give you five more minutes. Swallow the aphrodisiac next to you and be ready again.”

As Adler, who had been drained and withered from years of relentless, repeated sessions, braced himself for yet another brush with death, something unexpected happened.

“If you try to sneak out again, I’ll knock you unconscious and continue anyway, so... hmm?”

Charlotte, who had been lazily murmuring bone-chilling threats while exhaling another puff of smoke, was interrupted by the chime of a portable telegraph device in her pocket.

“Hmm... I see.”

“... Gulp.”

As Charlotte’s eyes narrowed while reading the message, Adler, trembling sporadically from the waist down, swallowed nervously, his face tense.

“Haaah...”

“A-A request? It’s a request, isn’t it? Please tell me it is.”

“Tch. Just my luck. The shift change is tomorrow.”

Unable to hold back, Adler blurted out his question in a flustered tone. Charlotte sighed deeply before responding in a voice laden with annoyance.

“Looks like I’ll need to step out for a bit. I should be back by evening.”

“R-Eeally? Are you sure you don’t want to stay out overnight?”

“Keep spouting nonsense like that, and I’ll pack you in my bag and take you with me.”

“... Have a safe journey.”

Adler, who had been practically begging, quickly folded his hands and bowed with exaggerated politeness at Charlotte’s menacing warning.

Charlotte, still eyeing him with a sceptical expression, pulled an overcoat off the wall and threw it over her shoulders, adding one final remark.

“By the way... you know, right? If you try to escape again while no one’s here, like last time...”

“T-That was a mistake. No, not a mistake— it was an act of God, you see? I mean, anyway...”

“... You’ll enjoy a fascinating and unforgettable month where your lower half won’t settle down for even a single second.”

Adler’s frantic rambling came to an abrupt halt at Charlotte’s chilling remark.

“Even though I’ve quit the drugs for the sake of the kids, I’m still continuing my research.”

“.......”

“So, behave yourself.”

With those final words, Charlotte stepped out of the room, leaving a heavy silence lingering in her wake.

“... Sniff.”

Time passed— how long, Adler wasn’t sure any longer.

He sat there sniffling, cursing his narrow-minded assumption that the aphrodisiac punishments were the worst he could face.

- Creeeeak...

“... Hic?”

The door, which he had believed would remain shut at least until nightfall, slowly creaked open.

“Wh-Wh-Who’s there...?”

Despite the highly negotiated rules of the grand pact, overseen by Professor Moriarty and Charlotte Holmes with great vigilance, there were still occasional breaches. Collaborators would sometimes sneak in and take advantage of Adler, ignoring the established order.

“If it’s Lupin, I’m pulling this cord! I mean it! This cord summons the professor in five minutes, okay? Got it?”

Truthfully, such incidents – led by the disgruntled thief Arsene Lupin, who had strong objections to the pact – were far from rare.

Thus, Adler’s panicked scramble to wrap himself in the blanket and clutch the emergency alarm cord was a pitifully understandable reaction.

“Please... I swear my brain’s about to melt at this rate...... Huh?”

“........”

“......!!!”

But something strange happened. Adler, gripping the cord with a face pale as a ghost, suddenly widened his eyes at the figure entering the room.

“Y-You’re here!!!”

Moments later, tears welling in his eyes, Adler jumped up and sprinted barefoot towards the visitor.

“Moran!!!”

“... You’re working hard, I see.”

The person Adler greeted so joyfully was none other than Celestia Moran.

And the reason was simple.

“I’ve been through so much, waaaaaah...”

“.......”

She was the last and only collaborator who had never once taken advantage of Adler or so much as hinted at wanting to.

“You’ve been through a lot, haven’t you?”

“Charlotte’s been feeding me 24-hour aphrodisiacs, and I’m so exhausted, I think I might literally die of overexertion! Actually, I already did once, but Poppy resurrected me...”

“It’s okay. Come here, Master.” 𝒻𝘳𝘦𝘦𝘸ℯ𝒷𝘯𝘰𝑣ℯ𝑙.𝘤𝑜𝘮

As if accustomed to this scenario, Moran naturally pulled Adler into a comforting embrace, patting his trembling back.

“Sniff... Moran, you’re the only one I can rely on...”

“... Is that so?”

“Yeah... You’re the only one who hasn’t, uh, you know, done anything to me.”

“I would never do such a thing to you, Master.”

Moran responded with a soft laugh, her voice gentle, as Adler poured out his tearful lament.

“... Unless, of course, it’s something you wished for, Master.”

“Eh, what’s that supposed to mean?”

Adler, now somewhat calmer, grinned brightly as he replied.

“Moran, you’ll always be like a daughter to me.”

“... Pardon?”

“In fact, if it were up to me, I’d adopt you on the spot.”

Adler, now standing on his tiptoes, reached up with some effort to pat Moran’s head, which had, at some point, grown just slightly taller than his own.

“And you shouldn’t be saying things like that when you’re not even an adult yet, okay?”

“......”

“Anyway, let’s just live like this – normal and happy – for the rest of our lives, alright?”

“............”

“... Right?”

As Moran suddenly fell silent, Adler, sensing an odd tension, glanced at her nervously and asked again.

“... Of course, Master.”

Moran, who had been quietly watching him, broke into a soft smile, reassuring Adler.

“Haha, right. That’s my Moran.”

“By the way, I brought it.”

“Huh?”

“The thing you secretly asked me to get last time.”

“Oh!”

Adler, who had been laughing along with her, suddenly widened his eyes, darting glances around the room in shock as Moran lowered her voice into a conspiratorial whisper.

“Liquor with a proof of over 60. It wasn’t easy sneaking it in—took longer than expected to bypass the professor’s security magic.”

“F-Finally...!”

As Moran subtly produced a small bottle of liquor from her coat, Adler trembled with barely contained excitement, his expression one of overwhelming gratitude.

“But what exactly are you going to do with it? Even if the alcohol helps you regain your old strength temporarily, there’s a limit to how many people you can handle at once...”

“I love you!!!!!”

“... Hngh.”

Adler suddenly leaned in and planted a kiss on Moran’s cheek, cutting off her cautious question. Startled, Moran froze in place, her expression unreadable.

“... As long as I can get out of here, that’s all that matters. I’ve got a last resort up my sleeve, after all.”

Ignoring her reaction entirely, Adler continued to pepper her with kisses, his giddy chatter spilling out in a rush of nervous energy.

“Don’t worry about being tracked. I’ll move so fast they won’t have time to react... Sure, it might get dangerous, but as long as you’re with me, Moran, I can handle anything.”

“... You really have no problem saying things like that so casually, huh.”

“The Omake Room. If I can just make it there somehow... Huh?”

Caught mid-sentence, Adler suddenly paused, sensing a chilling aura emanating from the person in front of him. He hesitated, his eyes flicking cautiously to Moran’s face.

“... What did you just say, Moran?”

“Oh, n-nothing. Just talking to myself.”

“R-Right? Haha. Must’ve been my imagination...”

Scratching the back of his head awkwardly, Adler let out a nervous laugh. Then, with a grin stretching wide across his face, he eagerly began uncorking the bottle of liquor he had finally acquired after so many years.

“Anyway, get yourself ready too. From now on, we’ll need to stay on high alert...”

“... Yes, this is entirely your fault.”

“Alright, then... gotta measure it out precisely, so I’ll start with just one sip...”

Completely absorbed in his excitement, Adler failed to notice Moran standing behind him, quietly stroking her cheek with a distant look in her eyes, muttering under her breath in a low, almost inaudible voice.

“... I’ve held back long enough.”

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Meanwhile,

“... So, you’ve finally arrived?”

In a dimly lit room, a woman sat silently, her gaze fixed on the faint light emanating from a peculiar machine. A slight smirk formed on her lips as she stretched leisurely.

“I thought my neck might snap from all the waiting.”

The light from the machine – strangely out of place in the 19th-century setting with its modern laptop-like appearance – shone upon the nameplate on the desk before her.

Headmistress of the Academy《Auguste Dupin》