Chapter 41: Stacking Passives
Regulus harbored a rather dangerous idea.
A killing blow against all carbon-based life — wizards included.
What compound was nearly universally lethal to carbon-based organisms, and could be generated on the spot via Transfiguration from readily available materials?
Cyanide.
Whether as hydrogen-cyanide gas or cyanide ions, both were viciously toxic — capable of shutting down cellular respiration almost instantly. The lethal dose was minuscule; onset was near-immediate.
The air contained nitrogen and carbon. Water vapor supplied hydrogen.
In theory, with sufficiently godlike magical control, one could instantaneously capture nitrogen, carbon, and hydrogen atoms from the surroundings,
forcibly combine them into hydrogen-cyanide molecules, and deliver them directly into the target's respiratory system...
What that demanded was no longer mere molecular rearrangement but a fantasy of atomic-level manipulation — and real-time elemental identification and synthesis-pathway computation rivaling a supercomputer.
At present, it was pure fantasy. But the wizarding world's defining feature was turning the impossible into the possible.
At the very least, this direction pointed toward the heights Transfiguration could theoretically reach in extremis.
It would cease to be a combat auxiliary and become the most covert, most lethal weapon imaginable.
If struck, a gifted wizard might manage some form of self-rescue. But an average wizard would almost certainly die.
Of course, that was impossibly remote — perhaps forever unattainable.
Still, one could work toward it.
Hermes managed to drag himself upright, bracing on his bedpost, head bowed, unable to look at Regulus.
His inner pride had been shattered utterly. In its place: deep wariness, deep fear, and — unnoticed even by himself — a warped curiosity about that unknown force.
His earlier fantasies of turning the tables through Dark Magic now seemed laughable.
He needed to re-evaluate everything — himself included — and figure out how to coexist with this terrifying roommate.
Silence settled over the dormitory. A faint, guarded smile tugged at Regulus's lips. He picked up a fresh piece of graphite and began another round of practice.
......
Exploring Transfiguration's relationship to the essence of matter was captivating, but Regulus knew full well it required years of accumulation and could not be rushed.
What he needed now were more immediate and critical defensive capabilities — to meet a threat growing ever closer: Voldemort.
Occlumency was the foremost priority.
Canon mentioned that Severus Snape had used it to serve as a spy under the nose of Voldemort — a master Legilimens — without detection.
Mastering Occlumency would not only defend against Legilimency but could also help resist the Imperius Curse.
It was an indispensable survival skill for anyone facing Voldemort.
Yet Occlumency alone was insufficient.
He turned his mind to passive magic — spells that operated continuously without active casting, or triggered automatically to protect the wizard.
The standard Hogwarts curriculum rarely covered these. They were generally considered advanced or obscure, scattered through the legacies of ancient families and certain high-level magical texts.
And Occlumency was the most essential passive mental defense among them.
For Regulus, entering the Restricted Section without permission was the kind of thing that happened either zero times or countless times.
Tonight — a Wednesday evening before Halloween — the castle was especially quiet. He decided to infiltrate again.
The process was second nature by now.
He did not linger. His targets were clear. Using his powerful mind's scanning-style reading, he rapidly browsed and memorized the core content of the relevant books.
He noted a number of titles:
"Fortress of the Mind: Essentials of Mental Defense"
"Ancient Protective Rites and Permanent Magical Inscription"
"The Nature of Magic: On Shaping and Disguising One's Personal Magic"
"An Overview of Dark Magic Detection and Countermeasures"
"Soul Resilience: On Resisting Imperius and Beguiling"
"Hidden Paths: Tracking, Counter-Tracking, and Magical Fog"
Hogwarts' library reserves were unfathomably deep. These titles also sketched for him the vast domain of knowledge he would need to explore in the future.
Back in the dormitory, Regulus immediately began practicing Occlumency.
According to the texts, the core of Occlumency lay in strict control of thought and emotion leakage, combined with the construction of complex, deceptive — or rigidly fixed — mental labyrinths deep in one's consciousness, designed to confuse any intruder.
Practice in stages.
First, the basic barrier: concentrating to build a simple wall around the outer perimeter of consciousness, blocking surface thoughts from being broadcast and read.
Second, mental organization and compartmentalization: sorting different memories, knowledge, and emotions into separate rooms.
Third, generating false memories and decoy thoughts: actively creating plausible-seeming but irrelevant or misleading mental fragments that would be automatically served to an intruder upon breach.
Finally, deep solidification and autonomous defense: training the defense mechanism into instinct so that even when not actively maintained, the subconscious would run the basic barrier and decoy deployment on its own.
Only the deepest, most critical thoughts would be heavily guarded, accessible only through extraordinarily convoluted pathways.
With a mind refined through Star-Orbit Meditation to far exceed most peers — and many adult wizards — in both strength and soul stability, Regulus found Occlumency's threshold nearly effortless.
He quickly mastered the basic barrier and handled compartmentalized mental organization with meticulous order.
He sensed, however, that reaching a level capable of fully deceiving a Legilimens of Voldemort's caliber would require considerably more practice and refinement of advanced techniques.
But the door was open. The rest was a matter of patient grinding and situational adaptation.
He even conceived an idea: could the Star-Orbit Meditation's dynamic model serve as a unique core for his mental labyrinth?
The most vital secrets would be hidden within the constantly running, computationally complex patterns of the star-orbit model.
An intruder who breached the outer defenses would face a vast, ceaselessly moving starscape requiring extraordinary computational ability just to comprehend — and would likely end up disoriented, unable to locate anything truly useful.
Over the next two days, alongside consolidating his Occlumency, he began exploring other passive magics.
The Permanent Shield Charm prototype he understood as a shaping of one's own magic — forming an exceedingly thin but uniformly distributed protective layer across the body's surface.
It demanded continuous, subconscious micro-adjustment of magical output, was highly taxing on attention, and at present could only be sustained briefly.
Danger Sense paired with his already-keen magical perception. He began deliberately training himself to register even the subtlest flickers of malice directed at him from the surrounding environment.
None of these passive magics were easy to learn or master.
They did not prize momentary explosive power. Instead, they required of the wizard an exquisitely fine-grained control of magic and mind, along with slow, long-term reshaping.
But the benefits were equally obvious.
Once achieved, they became true instinct — armor and radar operating twenty-four hours a day. They could provide warning before danger arrived,
furnish an automatic first layer of cushioning on impact, and shield the deepest secrets from prying eyes.
For someone who needed to maneuver within the dark camp, these capabilities were no less important than any formidable offensive spell.
......
Friday afternoon. Potions let out early.
Regulus headed to the library as usual, but in a secluded corridor linking the dungeon classrooms with the main stairway, he heard familiar commotion and jeering.
James Potter. Sirius Black. Peter Pettigrew. And Remus Lupin — who appeared to be trying, with limited success, to intervene.
They had cornered Severus Snape.
Snape's robes were drenched in some sticky potion residue that was giving off a revolting smell. His hair hung damp. His face was thunderous; his wand gripped white-knuckled. But against four — James and Sirius flanking him — he looked utterly isolated.
"Well, well — who's this? Our dear Snivellus running another one of his potion experiments? Brewing a new stink-bomb, are we?" James taunted loudly.
"Let me go, Potter." Snape's voice was raw with fury, the words forced through clenched teeth.
"Let you go? We're just helping you clean the unidentified substance off your robes. It really is filthy. Just like you."
Sirius lounged against the wall, face alight with rebel mischief.
Regulus stopped. He did not approach at once. He simply watched in silence.