Mary froze for a moment, then fell silent as if choosing her words.
After a while, she finally spoke.
"Mm… I'm thinking—assuming we don't damage the primary load-bearing structure… is it possible to exploit the building's inherent non-load-bearing redundant space—say, the closets of adjacent units—to create a kind of dynamic spatial connection?"
She asked with an air of scholarly seriousness.
Professor Fields' interest lit up instantly.
"Dynamic spatial connection…" he chewed on the phrase, not answering right away.
He picked up a piece of chalk and pulled down a clean section of blackboard.
Every eye in the tiered lecture hall turned toward him.
"An extremely intriguing idea, Miss Morstan," he said, sketching as he spoke. "This goes beyond conventional structural mechanics. It's closer to an architectural trick—more like… a magic act. A magic act about space."
In under a minute, two adjacent rectangles appeared on the board—almost exactly like the crude floor plan Mary had drawn in her notebook.
"In some early Victorian buildings—especially bespoke mansions built for the aristocracy—designs like this did exist," he continued. "Their purpose wasn't load-bearing. They were meant for… special functions."
"For example: a rotating bookshelf, with a passage to a hidden room behind it. Or two wardrobes in neighboring rooms whose back panels are movable—allowing a person, unnoticed, to move from one bedroom to the next."
He was utterly absorbed. Chalk dust fluttered down with each sweep of his arm. He looked like he'd forgotten the world existed.
"Of course, those are rather crude tricks. But what you proposed, Miss Morstan, is far more refined."
"Imagine a massive wardrobe. When it slides forward, the space behind it does not become empty—because another panel, disguised as a wall, slides in simultaneously to fill the gap."
"The whole process is like a perfectly fitted drawer: you pull one out, and another is pushed in."
"From the outside, the total volume of space doesn't appear to change. And yet, a passage has been silently opened."
The lecture hall fell dead quiet.
Most of the students were lost in the fog; they could only tell the professor was unusually excited—and the lecture was becoming even harder to understand.
Only Russell listened while staring at Mary's simple sketch, his brow gradually knitting.
Professor Fields had laid out a method, but if you tried to apply it in reality… something still felt missing.
Russell stood again.
"Uh… Professor, I have a question."
"Of course, Mr. Watson." Professor Fields paused and looked at him with expectant interest.
"Does the design you described have minimum space requirements?"
Russell clarified, "I mean… the space is made up of a living room and a bedroom. The living room is about ten square meters, the bedroom about nine. With dimensions like that… would your design still be possible?"
Professor Fields narrowed his eyes.
"Ten square meters and nine square meters…"
He set the chalk down and began pacing, muttering calculations under his breath.
"If we assume standard masonry thickness, the wall is at least 240 millimeters. If it's made movable, you'll need additional mechanical components and a reinforced frame. That alone will consume at least half a meter of thickness."
"Too thick. For a small unit with under twenty square meters total, doing this would make the space feel extremely oppressive. It isn't reasonable."
As he spoke, he rapidly filled the board with sections, lines, and formulas—until it became a private storm of thought that only he could interpret.
Most students gave up and drifted toward sleep.
To be honest, Russell couldn't follow anymore either.
He was just waiting for a clear answer.
Yes, or no.
Mary frowned as well, her fountain pen tapping lightly against her notebook.
Too complicated. Too expensive. Not reasonable.
That was what she was thinking.
"Logically, it's feasible," Professor Fields finally said. "But that's only in theory. In reality, the cost required to do it would be… considerable."
"Alright, I understand. Thank you, Professor—" Russell nodded, about to sit down—
When Mary suddenly stood.
"Then what if we double the existing conditions?"
"Double?" Russell turned to look at her.
Professor Fields looked uncertain. "Do you mean doubling the volume of the space?"
"No." Mary shook her head. "I mean: using the numbers Mr. Watson just gave as a standard—then adding an identical sample."
"In other words… if there are two apartments with the same layout and the same size, tightly adjacent—would it be feasible then, Professor?"
Professor Fields raised an eyebrow. He turned back and drew a second identical rectangle beside the first.
"If that's the case… then there may indeed be a possibility," he said.
"Mr. Watson, your earlier question limited my imagination. You provided only one closed system. But if…"
His chalk struck the shared wall between the two rectangles.
"If the system itself is composed of two units—then what changes?"
"W-what… does that mean?" Russell blinked, completely at sea.
Can you say that in a way I understand?
Otherwise, how am I supposed to explain it to Charlotte?
"Simply put." Professor Fields cleared his throat, tossed aside the short chalk nub, and picked up a fresh piece.
"With the conditions you gave, it's theoretically possible but practically impossible—because the space is too small."
"But if we add Miss Morstan's condition, we can distribute what would have been compressed into a single space across two spaces."
"Originally, the logic was to hide a passage inside the wall. Now, it becomes making the wall itself the passage."
"B-but… walls aren't hollow," Russell objected.
Professor Fields smiled, as though he'd expected that.
He didn't give Russell time to think. The chalk raced across the board, sketching a rough structural diagram.
"You only need to move the bookshelf wall on your side. The other side will move in sync, making room for each other—opening a gap large enough for a person to pass."
"When the movement ends, the gap closes, and everything returns to normal."
He set the chalk down.
"So rather than saying the wall isn't hollow… it's better to say: the part of the wall you can see isn't hollow."
"The truly hollow portion is already outside your field of view—hidden behind the massive bookshelf."
....
My Patreon : patreon/RuneA
If you want to read the novel in advance, you can subscribe for early access. I also have many more novels in my collection that you might be interested in
I upload ten novels a day, with 3 to 4 chapters per title depending on the length. If you're following a particular series, please wait your turn a little
If there's a particular novel you're enjoying on Patron, please give it a 'like' so I know to focus on it