Hearing Mary's words, Charlotte unconsciously frowned.
"Wait—did you just say Mycroft? Mycroft Holmes? He's covering for Moriarty?"
"Um…" Mary nodded, then gave Charlotte a curious look. "Didn't you already know?"
"How could I not have known something like that?" Charlotte muttered.
Silence fell again.
Mary and Charlotte stared at each other for a long moment, and finally, both turned to Russell at the same time.
"Explain, Watson," Charlotte commanded.
"Uh…This will take a bit of explaining," Russell scratched his head. "Mary and I thought you already knew."
"I'd like to know as well," Charlotte said coldly.
"What kind of shocking claim is it to suspect a British government minister is protecting London's most notorious thief?"
"Well, it's kind of a long story."
"That's perfectly fine," Charlotte said, glancing at the clock. "Unless, of course, you think this matter is so complicated that it can't be settled in just two hours."
"No, no—In any case, it all traces back to the Ethan Roy incident," Russell began, clearing his throat.
"Before we talk further, I need to fill you in on a bit of background," he continued. "Previously, Mycroft came looking for you on Baker Street, Charlotte."
"Right." Charlotte nodded lightly; she had heard about this already.
"So what happened next?"
"Well, you had a talk with Mycroft, didn't you?"
The day after telling her about it, Russell mentioned it to Mary while chatting.
After hearing this, Mary began pondering Mycroft's behavior.
Russell glanced at Mary as he recounted it.
"What do you think?" Charlotte pushed for a conclusion.
"Mycroft's actions were just… too unusual," Russell said. "From every angle, Ethan Roy was the one who stood to gain the most from his downfall."
"At such a climactic moment, instead of focusing on eliminating Roy's subordinates and consolidating his own position, Mycroft was wasting time on an elusive thief."
"So, you think he was trying to distance himself?" Charlotte prompted.
Russell nodded. "His desperate attempts to distance himself from Moriarty clearly indicate some illegitimate tie between them."
"That was our first guess at the time," he admitted.
"Utter nonsense," Charlotte retorted without hesitation. "Mycroft may be a boring, but he's not that incompetent. To use such clumsy tricks to create distance—especially in front of me—that's just not his style. Does he really take me for a fool?"
"Exactly," Russell said. "And that's what became our second big question at the time." He glanced at Mary, giving her the floor.
Mary accepted the baton with a nod.
"Russell and I both thought, given Mycroft's intellect, it made no sense for him to commit such a rookie blunder."
In the quiet classroom, Mary's clear voice rang out with a kind of musicality.
She stood up, walked to the pristine blackboard at the front, picked up a piece of chalk, and started teaching the two like she was the teacher and they the students.
"And so, we landed on the second—and far more plausible—deduction," she said. "What if those actions Mycroft took weren't really about creating distance, but about giving Charlotte a subtle hint?"
"He was dropping clues in such a roundabout way that only you, his sibling, could decipher."
Charlotte stayed silent, gesturing for her to continue.
"He deliberately used office jargon guaranteed to annoy you, and intentionally accused Moriarty—the person you dislike—of 'political meddling.' All to provoke your defiance and disgust, and steer you away from digging any deeper."
Mary wrote the names "Moriarty" and "Mycroft" on the blackboard and drew a line between them.
"It's the ultimate win-win bet," she continued. "If his hint worked and you lost interest in Moriarty, his goal would be achieved—he'd have protected his most vital chess piece."
"But, even if you didn't get the hint and, in a fit of defiance, became obsessed with Moriarty and finally caught him, it wouldn't necessarily be a loss for Mycroft."
She reinforced the line between the names with thick chalk.
"Logically, at that point he could accuse all of Moriarty's crimes—including the Lloyds Bank job—of 'endangering national security.' He'd win political points for upholding justice, cut ties with Moriarty entirely, and publicly distance himself."
"In other words: whether you accept it or not, he wins either way."
She put down the chalk, dusted the powder off her hands, and smiled at Charlotte.
"It's a perfect, flawless, and conspicuously showy plan—classic Mycroft style, right?"
The classroom was still.
Charlotte leaned back in her chair, fingers steepled before her, eyes fixed for a long time on the blackboard covered in Mary's deductions.
After a lengthy silence, she finally spoke—her rare agreement evident in her tone.
"An intriguing conclusion," she said. After a pause, she glanced at Russell. "Seems you didn't spend all your time in class sleeping, after all."
"Well, I did pay my tuition," Russell shrugged, breathing a tiny sigh of relief inside.
"But, honestly, I still don't quite buy that premise," Charlotte shook her head. "Maybe Mycroft has some secret weapons I don't know about, but, from what I know of his character, I really can't see him doing such a thing."
"Why not?" Mary asked.
"If he was actually trying to suppress a political rival, he wouldn't need such extreme tactics," Charlotte said. "He'd gradually erode Ethan Roy's influence, eventually shutting him down—all without unseating him directly. That way, he'd maintain control long term."
Which is harder to deal with: a pile of bones, or a living person?
Charlotte countered with a question.
Russell and Mary fell silent for a while.
Finally, it was Mary who spoke next. "Actually, that's very easy to test."
"We can ask directly."
"How so?"
"Just call Mycroft," she said with a smile. "Ask him whether he's covering for Moriarty."
"Of course not that directly. Let's do it your way."
"Didn't you just say you wanted to rattle Moriarty a bit?"
"Tell Mycroft you're heading to Buckingham Palace. Then, watch how he reacts, and see what happens next while you're there."
She paused, then added, "It's the perfect timing. I know a place on campus where we can make the call."