Chapter Text
The science wing smelled of ethanol and bleach, sharp and sterile, yet somehow suffused with the faint residue of tension that clung to Class 1-A after the USJ attack. Silence was thick, heavier than the walls themselves, and yet the students moved as though aware of some invisible rhythm, each footstep a cautious negotiation with the memory of smoke, fire, and the near certainty of death.
Shoto Todoroki entered first, methodical, controlled, every movement precise. His dual-colored eyes swept the room, cataloging every detail: polished benches, meticulously aligned glassware, the faint metallic tang in the air. His calm exterior was deliberate, yet the quiet of the aftermath pressed against him, echoing in the spaces where fire and ice had both left scars.
Bakugo stormed in seconds later, boots striking the floor like detonations, scowling even at the empty desks. The air seemed to tense around him, responding to the restless energy that barely contained itself within his body. Todoroki noted the tension without looking, as if the air itself were a barometer of intent, and felt the faintest tug, subtle and unacknowledged, between himself and Bakugo.
Professor Takahashi stood at the front, his black waistcoat buttoned meticulously, sleeves rolled with care. His spectacles caught the light, gleaming without distraction. He made no effort to soften the room, no attempt to coax his students into comfort. Instead, he allowed the silence to stretch, to settle, before drawing three simple words on the board:
Ionic. Covalent. Metallic.
“Three ways atoms cling to one another,” he said, measured and deliberate. “Three ways matter refuses to exist alone. Ionic bonds are theft: one atom loses, another gains. Covalent bonds are trust: electrons shared between partners. Metallic bonds are communion: strength drawn from many, distributed, enduring. Each requires energy to form, and energy is released when the bond is stressed.”
Mina, sitting near the front, twirled her pencil nervously. She wanted to lighten the mood, perhaps make a joke, but the room’s intensity reminded her of smoke and alarms, of the screaming that still haunted the halls in her memory. She let the pencil turn in her fingers instead, her gaze flicking to Bakugo, noting the restless energy radiating from him like static.
Kaminari tapped his fingers on the desk, a jittery rhythm in response to both the lecture and the charged atmosphere. He observed the subtle tension between Todoroki and Bakugo, feeling as if he could almost see the energy passing between them, though neither acknowledged it. The heat of Bakugo’s temper met the icy precision of Todoroki’s control, a reaction forming quietly but undeniably.
Yaoyorozu’s mind mapped the chemical principles effortlessly, noting how the physical energy in the lab mirrored the metaphorical energy between classmates. Metallic bonds—distributed strength—seemed almost a poetic reflection of cooperation, while ionic bonds’ abrupt transfers mirrored Bakugo’s bursts of force, covalent bonds Todoroki’s measured restraint.
Iida straightened in his seat, silently noting the order and chaos coexisting in the room. The juxtaposition between Bakugo’s impatience and Todoroki’s calm struck him as a living demonstration of energy transfer—both chemical and human.
Professor Takahashi’s voice cut through the quiet. “Which bond is strongest?”
Bakugo’s voice snapped like a spark. “Metallic. They don’t break.”
Takahashi’s gaze lingered, assessing. “And why?”
Before Bakugo could elaborate, Todoroki’s voice answered instead, calm and precise: “Because the attraction between positive ions and delocalised electrons requires great energy to overcome.”
Two halves of a truth, the professor murmured internally. Strength is understanding, yes, but endurance is application. One without the other is incomplete. Energy is both input and release; bonds, whether chemical or human, require effort to form, and they can fracture unexpectedly.
The lecture moved into the practical. Neutralisation. Hydrochloric acid met sodium hydroxide. A rise in temperature, a simple exothermic reaction, a measure of energy released. Pairs were assigned, and by some quiet inevitability, Todoroki and Bakugo were placed side by side.
Bakugo grabbed the beaker with sharp precision, impatient. “Don’t slow me down,” he muttered.
Todoroki placed his hands carefully, deliberately. “Try not to break it,” he said softly, a subtle edge under the calm, almost challenging him in return.
As the solution reacted, heat rising, steam curling between their hands, their movements mirrored the principles being taught. Ionic bonds—abrupt energy transfer, rapid shifts—was Bakugo, violent, impulsive, forceful. Covalent bonds—shared, careful, directional—was Todoroki, precise, deliberate, observing, restraining. Metallic bonds—the collective endurance, distributed strength—hinted at what might be possible if the energy between them were harnessed, rather than resisted.
Mina’s pencil spun between her fingers as she glanced at the pair. The room felt like it held its breath, watching sparks that weren’t entirely physical, noticing the subtle energy in the space between two classmates neither acknowledged.
Kaminari fidgeted, eyes flicking back and forth. He imagined the heat and frost mixing, energy neither fully contained nor unleashed, waiting for a tipping point. His own hands itched to touch the lab equipment, to measure, to make sense of it in numbers, but the atmosphere was denser than chemistry alone.
Yaoyorozu noted the reactions on the bench and in the air. The energy Todoroki controlled, the force Bakugo released—they formed a dynamic equilibrium, a system not yet stable, not yet at balance, but resonant, undeniable.
Iida kept his posture straight, silently noting the lesson. Observation was as crucial as action; energy could not be measured solely in joules, nor could bonds be understood solely in theory. One had to watch carefully, account for variables, notice the reactions that were invisible but present.
As the reaction progressed, Todoroki noted: “Temperature change: thirteen degrees.”
Bakugo punched numbers into the calculator, forcefully, impatiently. “Five thousand four hundred joules. Done.”
Neither spoke further, yet the room was charged. Metallic, covalent, ionic—the principles intertwined, mirrored in human behavior, mirrored in quiet tension that throbbed between two extremes.
Professor Takahashi moved among the students, observing: hands, posture, expressions, subtle gestures. Energy is not only released through chemical reaction, he thought. It exists in the interplay of forces, in restraint and release, in patience and impulse. Some reactions are immediate; some build quietly, until the right conditions bring release.
When the practical concluded, Takahashi left one line chalked beneath the three words on the board:
The strongest bonds take time. Energy is released when stressed. Endurance requires both restraint and willingness.
The class filed out quietly, boots echoing against polished floors, voices muted. Todoroki lingered, eyes tracing the chalk, considering how restraint and release defined both chemistry and survival.
Bakugo shoved his bag into place, muttering under his breath, irritated yet aware of a heat he could not extinguish, a reaction forming in silence that neither could yet name.
From behind, Ashido whispered to Jirou, “Do you feel that? Like… electricity or something?”
Jirou leaned back, listening, noting the unspoken energy. “Yeah,” she murmured. “Something’s happening.”
Even Kaminari, who tried to stay detached, felt it—the air charged with anticipation, with heat, with controlled fire.
And in the quiet aftermath, Todoroki and Bakugo left the room without acknowledging each other, yet the invisible bond persisted. It had begun. It would endure.
No one yet knew what it would release.
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