Russell raised an eyebrow at how quickly Mary had calculated the number. "How can you and Charlotte do math so fast?"
"It's simple," she said flatly, setting her sandwich down. "It's a six-digit password. Each digit is 0–9; repeats allowed. It must contain at least one 8 and one 9. Total possibilities: 1,000,000. Subtract the cases missing an 8 or a 9 (531,441 × 2) and add back the overlap (262,144). Result: 199,262 possibilities."
Russell stared at her calm face for a long moment. Aren't western supposed to be bad at math?
"In other words, nearly 200,000 possibilities," Mary said, erasing the blackboard. "Finite, yet practically infinite. Trying 200,000 combinations one by one is impossible, right?"
"Absolutely not," Russell shrugged.
"Charlotte and I aren't that stupid."
"Then what does Charlotte plan to do?" Mary asked curiously.
"I have no idea," Russell admitted. "She suggested to Vanessa that we might bypass Charles' trigger zone by having him record the numbers unconsciously—through subconscious or muscle memory."
"Subconscious… muscle memory?"
"For example, I want you to memorize six digits. After you write them down, you might forget them for subjective or objective reasons. But your brain and body have already recorded them without you realizing it. Later, when you're given six random digits, those will probably be the password I wanted you to remember. Just like learning to ride a bicycle—even after years, you can get back on and ride without thinking."
Mary nodded thoughtfully. "That sounds like a good idea… but putting it into practice won't be easy."
Russell sighed. "Dr. Vanessa says Charles' mental state is very unstable right now. We can't afford any more mistakes. If we provoke him further, his brain's self-defense mechanism will kick in and he'll forget everything."
A faint light flickered in Mary's eyes; inwardly she breathed a sigh of relief, though outwardly she looked concerned. "That's… unfortunate. Has this path been blocked too?"
"At least for the short term." Russell shrugged and finished his sandwich. "Our only hope now is that Lestrade arrests Billson quickly or finds new leads on Emily Collins."
"Who is Emily Collins?"
"The maid at the Hannigan residence. She's the one who sold the fake news of Moriarty's death to the newspapers."
"Ah, her." Mary suddenly understood. "But why are we looking for her? Shouldn't we sue for defamation or fraud?"
"It's a newspaper matter. Nothing to do with Charlotte or me. The main reason we're looking for her is because she may have some connection to Billson."
"Her and Billson too?" Mary looked even more confused. "What's their relationship?"
"Good question. I'd like to know the same thing. But they are connected somehow." Russell told her about the envelope of cigarette butts Moriarty had sent to Charlotte.
Mary stared blankly for a second, then burst out laughing. "What's so funny?"
"N-Nothing…" She tried desperately to hold it in, shoulders shaking, and looked up at him. "I just feel that Moriarty is… in a sense… like a child."
"A child?"
"They're very similar," Mary said, resting her chin on her hands, blue eyes gazing affectionately at the puzzled Russell. "At first he was treated unfairly and became the target of public criticism, yet he did nothing. Even when The Times and The Guardian proved his innocence, he never appeared or spoke. I naturally assumed he didn't care at all—until you told me he sent that envelope to Charlotte."
She laughed again. "First of all, he originally had no idea that the person who sold the story to the newspaper was Emily Collins, right?"
Russell avoided a direct answer.
"Then why did he go to her apartment afterward?" Mary smiled. It was speculation, but it also questioned the man's true intentions.
"Because he knew she was the one who sold the information."
"Yes. But how did he know?"
"…Because he went to the newspaper himself?" Russell tried. Mary's smile deepened; she could see him scrambling for excuses. "And I think it's possible they used a messenger to relay the message again."
"…That does sound reasonable."
"It's basic thinking, Russell."
Pride was obvious in her tone. "Look—he may seem indifferent on the surface, but he's still furious inside. That's why he went out of his way to find out who was badmouthing him. When he tried to confront the person directly, they had already fled. So he searched the entire house and found some valuables. Then he came up with the idea of using Charlotte to send those items to Emily Collins—repaying a favor while also killing two birds with one stone. Look, isn't this just a child who cares far too much about saving face?"
…
…
PS: Please support me and read advanced chapters at patreon.com/AbsoluteCode