Becoming Professor Moriarty’s Probability

"... Haaa"

Several hours after Isaac Adler, who had gone missing, was found in the dilapidated warehouse,

- Lick...

"""........."""

The three girls, gathered in the client's living room, were glaring at Adler with a frigid gaze, who was seated on the desk while swaying his butt and grooming himself like a typical cat.

"... Where are the client and the professor?"

"They've gone to the university for classes. It's amazing that the professor was able to attend the classes after crawling around in such a state all night."

"Hmm. I see..."

In that situation, Gia Lestrade was the first to speak up and ask. When Charlotte responded in a relatively calm voice, she cautiously observed her for a brief moment before posing another question.

"Purr?"

Matching the tone of his cat-like voice to a questioning one, Adler tilted his head to the side, staring back at the three girls looking intently at him.

"Why has Isaac Adler deteriorated to this extent?"

"... I'm not quite sure, but the situation seems pretty serious."

Rachel Watson, who had repeatedly tried to restore him to his original state, slumped on the sofa and murmured in a tired voice.

"I'm a surgeon, not a psychiatrist. There's nothing I can do about this problem."

"... Indeed, I've heard that the respect and status of the psychiatric field have elevated since the development of magic."

"That’s primarily because magic, mystery, and bizarre phenomena are causing people to lose their minds. If it were a visible wound, at least there would be something to treat, but mental issues like these can't be fixed even with magic..."

And with those words, silence enveloped the room.

- Sneak, sneak...

Sensing the tense atmosphere amid the silence, Adler quickly moved down to the floor and started heading towards the sofa.

"... Meow."

Then, jumping next to Watson, who looked the least pleased among the bunch, he began rubbing his head against her side.

- Purr, purr, purr...

"... Haa."

Watson, still staring at him with a cold look in her eyes, finally sighed and began stroking his chin in response to his continued gestures of affection.

"Um, excuse me..."

".....?"

Glancing from the side and observing the whole spectacle, Gia Lestrade soon moved closer to the sofa, quietly, and squeezed herself next to Adler.

"Do you... want to play with this?"

"... Meow!"

“Ah…”

Hesitantly, she pulled out a toy mouse from somewhere and waved it in front of Adler. Seeing the toy, Adler’s eyes twinkled in delight, and he immediately snatched the toy away from Lestrade.

- Thump, thump...

""........""

Then, as the girls looked on, Adler started playing with the mouse in a typical cat-like fashion.

"... Huff."

"You, you shouldn't eat that!"

"Bleee..."

Having grabbed the toy mouse in his mouth, he beamed with a happy smile, acting like he was about to enjoy a good meal. However, when Lestrade reprimanded him, he spat the toy out and lowered his head with a crestfallen look.

- Swoosh...

Afterwards, coiling up between the two women, he finally closed his eyes and fell asleep.

"Watson."

"... Yes?"

"Forgive me in advance, but Isaac Adler is currently my husband."

"And?"

Watson, whose head was bowed down in silence, looked at Lestrade who had approached her with a face asking what she wanted to say.

"... I want to be the only one to pet my husband."

"But this isn’t Adler, it’s just a cat."

The next moment, a strange tension began flowing between the two women.

"Isn't it okay to pet a cute cat?"

"... Why are you doing this?"

Despite Lestrade's firm discouragement, Watson, who had been stroking Adler's head, muttered in a subdued voice… a dark expression plastered on her face.

"... Anyway, his face is bloody handsome. Fuck."

"Miss Watson..."

"Is it because I have been rejected recently? I hate myself for finding a younger man, coiled up on my lap like a cat, utterly adorable."

"Do you still insist that Isaac Adler and Neville St. Claire are entirely different beings...?"

"Since it has come to this, why not just let us take turns looking after him without trying to cure him?"

At her calm statement, Lestrade, visibly stunned, hurriedly rose from her seat.

"Miss Holmes, I think this place is dangerous. Mr Adler and Miss Watson as well, everyone is going crazy, don’t you think?"

"........"

"There must be a monster here causing mental breakdowns or hallucinations. We need to get out of here quic..."

"Honestly, wouldn't this be better for you, Inspector?”

Startled by Watson's still calm voice, she trailed off mid-sentence.

"Just think about it. From a social menace making a living off his face to an entity that doesn't even glance at other women except for you and even acts coy sometimes.”

"That, that’s not really it though. It’s more like… like he became a cat…"

"That's the good part. This uncontrollable devil has become harmless, even behaving affectionately. Don't you think it's a fitting end for such a creature?"

As her words continued, not only Lestrade, but even Charlotte, who had been quietly looking into the fireplace, seemed shaken.

- Swoosh...

Suddenly, Isaac Adler opened his eyes, jumped up, and leapt off the sofa.

- Crunch...

"..... Ouch."

He swiftly moved next to Charlotte, hugged her from behind, and plunged his canines into her neck, causing Rachel Watson's expression to turn icy in an instant.

"Why is he behaving like that all of a sudden? Has he turned into a vampire cat?"

"... That's just typical cattish behaviour."

"Behaviour, what do you mean…"

In the midst of this situation, Lestrade, looking perplexed, couldn’t help but ask. On the other hand, Watson, with a dark sheen in her eyes, silently watched the scene unfold before replying in a dangerously low voice.

"Male cats tend to bite the nape of the female they desire to mate with."

With those words, a cold atmosphere began spreading in the mansion's living room.

"Let's stop this nonsense and focus, everyone. I'm going to explain the plan now..."

- Creak...

"... Ah."

Trying to maintain her composure in this strange atmosphere, Charlotte let out a moan as Adler's teeth sank deeper into her nape.

"... I'll explain the plan."

"In that state?"

She briefly bit her finger and winced, then glanced back at Adler, who was still nibbling on her nape from behind before continuing.

"Initially, I thought this case was related to the recent trend of the elixir of immortality."

"... Immortality?"

"When Dr Frankenstein was arrested, documents found in her lab were leaked. From there, it has become all the rage these days in the back alleys, from what I hear."

"Hmm..."

Ignoring Adler, who was squirming behind Charlotte, Lestrade and Watson nodded in agreement.

"The method is simple. It involves injecting a certain amount of medicine made primarily from the serum of animals like dogs, cats, or monkeys into the body."

"Does that really work...?"

"I've only heard about it in rumours, so I'm not sure. There are a few records that it has been used since ancient times as an aphrodisiac or to restore the elasticity of the skin..."

"... It does seem plausible."

Upon hearing her explanation, Watson interjected with an intrigued expression.

"I've read a few papers during my university days. There was speculation that injecting small amounts of animal serum could indeed have such medical effects..."

"... Then you know about the side effects too, right?"

"Ah, well... yes? It was quite an interesting paper after all..."

At Charlotte’s question, Watson began recalling the information she had read, silent for some time.

"One of the side effects is that… for a few hours, you might behave like the animal whose serum was used... wait....."

Her eyes widened immediately.

"Could it be?"

"Yes, that’s what I thought too for a few hours. If you see the professor's insane actions towards the dog, she probably injected herself with the serum of a monkey or a dog."

Charlotte murmured subtly, stroking her chin.

"There has been quite a bit of evidence to back that too. The professor headed to Bohemia where the drug trade has recently increased to a dramatic extent. Not to mention, she also got furious when her son touched the experimental equipment. And crucially, the bizarre behaviour she displayed yesterday, which was different from any drug-induced hallucination or sleepwalking..."

"Right, the professor is set to be remarried. That solves the reason why she used the youth-restoring drug."

"So... the mystery is solved, right? And Adler should be back to his usual self in a few hours… so isn’t the case solved now?"

"... No."

However, to Lestrade's hopeful inquiry, Charlotte shook her head firmly.

"Why not?"

"Because there were no injection marks anywhere on Isaac Adler's body."

Charlotte began murmuring with narrowed eyes.

"And besides, do you really think a being called the King of Vampires would suffer side effects from just animal serum?"

"You, how do you know there are no needle marks on Adler's body…?"

"Did you strip him naked?"

"That's not the point."

She brushed off Watson and Lestrade's sharp questions and continued speaking.

"Finally, even if Adler somehow injected himself with the serum, it would be strange for him to experience side effects immediately after the first dose."

"........."

"If things are like this, maybe we need to change our perspective?"

As she spoke, she suddenly picked up the detective coat she had laid aside and began giving instructions.

"Watson. Get me a paper on the serum immediately. I need to scrutinize its credibility."

"Eh? Hmm, alright..."

"And Inspector, come with me."

"Uh, where?”

At the inspector's puzzled voice, Charlotte pointed towards a faintly visible building beyond the window and replied.

"Cambridge."

"Ah..."

"I need to see the professor's fiancé with my own eyes."

At that very moment, Adler, fully focused on Charlootte’s nape till then, suddenly looked up with a quiet gleam in his eyes.

".......?"

"What is it?"

"... It's nothing."

.

.

.

.

.

"Hey, Mr Adler, it's time to let go."

As Charlotte prepared to leave for her investigation, she sighed and began reaching behind her to free herself from Adler’s bite.

- Prrrrr...

"Ah..."

However, as Adler put even more pressure on her body at that moment, Charlotte lost her balance and fell to the ground.

"Haah...!"

"........"

Adler naturally overlaid on her back, growling softly into her ear as if to keep her still.

- Crunch...

"... Ugh."

Then, as he bit into the nape of her neck again, Charlotte, who was trying to push herself up from the floor, froze in place.

"One can't really argue with a cat..."

"... I guess I really should just kill him."

"Meow!"

Adler, busy burying his head in Charlotte's hair, was soon subdued by Watson and Lestrade, who each grabbed his arms and legs.

"Please stay here quietly."

"Meow?"

"Um, just in case, I’ll put a bowl of milk right here for you. And some toys..."

Tied to the sofa with a leash, Adler watched Charlotte and Watson while Lestrade sneakily approached him and whispered.

- Lick...

"Don't drink it right now..."

Staring down at the milk bowl in her hand, Adler began to lick it, burying his face inside the warm milk.

"... Purr."

"Ah."

Then, lifting his head and licking the milk off his lips, Adler squinted his eyes and let out a pleased sound, causing Lestrade's gaze to waver slightly.

"... He really is cute."

"Meow?"

"Oh, anyway! Don’t go anywhere and stay right here!"

However, immediately shaking her head, Lestrade stood up with a flushed face.

"It is said that only this much is considered normal and should be maintained daily…”

"Meow~"

"Getting distracted every now and then is a separate matter, though."

Then, with a momentarily subdued gaze, Lestrade stroked Adler’s chin and moved towards the exit, leaving behind Adler who rubbed his cheek against her hand with a cheerful expression.

"... If you avoid mischief, I might really consider getting married for real."

With those words, the mansion's door closed, and a long silence began enveloping the living room.

.

.

.

.

.

"... Hmm."

And the one who broke the stifling silence was surprisingly Adler, who was quietly sitting on the sofa, like a typical human, with a leash around his neck.

"Is this why it's called The Creeping Man?."

Although he had momentarily prevented the probability collapse with a cat act that wasn't in his nature, now, he needed to create a plausible ending before they returned to the mansion.

Meow~

"... I feel like killing myself, damn it."