Cuthbert and Alex were at the small table by the window playing wizard chess when Regulus returned to the Slytherin dormitory.
The board had clearly reached a stalemate. Both of them sat hunched over the pieces, brows furrowed in concentration.
Cuthbert's queen was berating Cuthbert. Alex's king was berating Alex.
The door creaked open. Both looked up at the same time, glanced at him, then dropped their gazes back to the board in perfect unison.
Nothing overtly suspicious about it. And yet somehow that made it worse.
Regulus ignored them. He was only here to wait for Madam Pince to finish closing up the library before heading to the Restricted Section.
He'd barely sat down when a string of profanity erupted from the chessboard, courtesy of the king. The language was crude enough to suggest this wasn't a set marketed toward young wizards.
Then Cuthbert spoke, hesitant. "About that thing..."
Regulus looked up.
"What happened last time. Can I tell my family?"
Regulus knew he meant the Astronomy Tower. He tilted his chin slightly, signaling Cuthbert to go on.
"I promised you I wouldn't tell anyone." Cuthbert's thumb traced the carved mane of a knight piece. "But I've been thinking. It involves the Macnairs and the Mulcibers. Hermes was badly hurt, that place was dangerous, and there has to be something behind it that we don't understand. I think my family should know."
His expression was serious, his tone careful, asking rather than telling.
In the days since, the reality had sunk in. He might have stumbled into the crossfire of some game being played between pure-blood families. His instinct was to go to his own family for guidance, or at the very least, to report what had happened. But he remembered the promise he'd made, so he was asking first.
Regulus studied him.
Cuthbert was right. The Averys should know. And so should the Rosiers. Even as a branch family, the Rosiers were unlikely to involve themselves directly, but being informed was a different matter entirely.
And Regulus was thinking further ahead.
If Voldemort's shadow really did lurk behind the Astronomy Tower incident, then the simple fact that Cuthbert had been involved and walked away unscathed could influence how the Avery family positioned itself in the future.
He glanced at Alex.
"Tell them when you go home for Easter," Regulus said, his voice even. "Don't write it in a letter. Say it in person."
Cuthbert nodded. Alex followed suit.
"There are things you don't know," Regulus continued. "For example, Abros Mulciber was fully aware that Darren Macnair was the one who hurt Hermes. He knew, and instead of exposing him, he helped cover it up."
Cuthbert's eyes went wide.
"Why?" Alex whispered.
"I can't tell you the specifics," Regulus said. "If Mr. Avery and Mr. Rosier want answers, they can inquire through the House of Black."
Neither of them knew what had actually happened. They didn't know what Abros's shifting behavior meant, and they certainly didn't know what lay hidden behind the stone door.
But once they told their parents, Mr. Cuthbert and Mr. Rosier would understand there was something deeper at play. The key information rested with Regulus. If they wanted it, they'd have to come through him, or through the Blacks.
Cuthbert and Alex exchanged a look but asked nothing more. The Astronomy Tower incident had built a deep trust in Regulus. If he said he couldn't tell them, then he had his reasons.
Silence held for a few seconds. Cuthbert's throat bobbed as he swallowed, and the words slipped out before he could stop them. "Regulus, that Evans girl..."
Regulus raised his eyes. His face was blank, but his gaze settled directly on Cuthbert's.
The words died in Cuthbert's throat. His mouth opened, then closed. Finally he turned away, pretending to study some irrelevant piece on the board.
Alex shook beside them, shoulders trembling with barely suppressed laughter.
Regulus didn't bother with either of them. He stood, slid his wand into the inner pocket of his robes, and pushed through the dormitory door.
As it clicked shut behind him, he heard a burst of laughter, equal parts embarrassment and curiosity.
---
The corridors of Hogwarts lay empty and silent in the deep hours of night.
Regulus moved along the wall under a refined Disillusionment Charm, his body blending seamlessly with his surroundings.
The Astronomy Tower had made two problems impossible to ignore.
Against sustained, wide-area attacks, he lacked any efficient means of answering in kind.
And in enclosed spaces where Apparition was blocked, his mobility was dangerously limited.
Fiendfyre, the kind of magic that consumed everything in its path... the cost of losing control wasn't something he cared to pay. But he understood its principles well enough that if the moment demanded it, he could cast it. Other ideas were taking shape too, with clearer targets in mind.
The mobility problem, though, needed solving now.
Space Warp was still immature. His Patronus couldn't carry him yet. Apparition could be shut down by anti-Apparition wards.
He needed a way to move fast that didn't rely on spatial magic.
Physically, the ongoing refinement of Star Guided meditation had pushed his body well beyond what any young wizard could match, and past most adults too. If someone assumed that neutralizing his spellcasting would be enough to subdue him, they'd learn a painful lesson.
But raw physical speed had a ceiling. To control a fight, he needed magic.
Deep in the Restricted Section, dust coated the shelves along the far wall.
Regulus ran his fingers along the spines, extending his magical perception outward.
Early on, this method of reading had been brutally taxing on the mind. Now he could sustain it for a full hour without noticeable fatigue.
He found several books that looked promising.
Wizard Mobility Tactics: From Basic to Advanced, written by an eighteenth-century Auror commander. It documented in detail how to leverage terrain and spell combinations to maintain a movement advantage in live combat.
A theoretical work on non-spatial displacement magic. Dry, but thorough.
Regulus started with the first book.
It outlined several spells.
The Swiftness Spell dramatically increased the caster's movement speed after activation, similar to an enhanced sprint. A faint white glow would coat the body, and at full speed the caster could leave afterimages. Pure speed augmentation, nothing more. The caster still ran on their own legs. Anti-Apparition wards couldn't touch it.
The Sprint Spell was originally a deceleration charm. Cast in reverse, it enabled inertia-free dashing: rapid acceleration, sharp turns, no risk of losing control at high speed. Tactically versatile, ideal for short-range breakthroughs, and compatible with shield charms. Anti-Apparition wards had no effect on it.
The Side-Shift Spell was a simplified version of Apparition. No full Apparition required, just a short-range lateral displacement. Agile enough for dodging attacks. Low magical cost, but couldn't be used in rapid succession. Best suited for quick repositioning mid-combat. Anti-Apparition wards could suppress it, but only weakly.
The Flight Spell built on the principles of object levitation. At an advanced level, it could be applied to the caster's own body for short-range flight or gliding. By modulating magical output, the caster could move slowly or cross obstacles without a broom or any other tool. Slow, with no offensive capability, but useful for low-altitude movement, clearing trenches, or scaling walls.
Regulus committed the principles and wand movements to memory and closed the book.
Every one of them had its uses. Every one of them had obvious flaws.
The Swiftness Spell was just running. The Sprint Spell was short-range. The Side-Shift Spell was short-range with a cooldown. The Flight Spell was slow.
He needed something more comprehensive.
---
The Room of Requirement answered his need, reshaping itself into a vast training space.
Dark wooden floorboards stretched across the ground. The ceiling soared so high it vanished into shadow. Clusters of magical light hovered in the air above, casting an even, steady glow.
Regulus started with the simplest option: the Swiftness Spell.
Wand pointed at himself, he spoke the incantation. "Celeritas."
Magic poured from the wand tip and flooded through his body. A faint white luminescence rose from his skin, but there was no other sensation.
He took one step forward. His body launched like something spring-loaded, covering ten meters in an instant.
Impressive burst speed, but at its core it was still running. Turns and sudden stops were limited.
Next, the Sprint Spell. His wand traced a specific pattern. "Momentum Arresto."
He stepped forward and his body began to glide, accelerating steadily. The straight-line sprint was solid. He tried a turn and found the handling responsive, but the range was disappointing. Less than ten meters before he came to a stop.
He picked a point ten meters out, focused, gathered his magic, and flicked his wand and used Side-Shift Spell.
His body materialized at the target position.
The Side-Shift Spell was the most stable of the group. Smooth execution, almost no discomfort. He tested it several times in succession and found the maximum effective range was roughly fifteen meters. Beyond that, the success rate dropped sharply. Each use also required about two seconds of cooldown.
Then again, this was Hogwarts. There was hardly a stronger anti-Apparition ward anywhere in the wizarding world. The results would likely be better outside these walls.
The Flight Spell was the most awkward. His body hovered half a meter off the ground, propelled forward by directed magical force slowly. Turning and braking both demanded precise control over his magic output, and the slightest lapse sent him off balance. The mental effort of adjusting his posture in midair cost roughly three times what ground movement did.
Regulus stood in the center of the training floor and reviewed each spell's strengths and weaknesses.
The Swiftness Spell had explosive speed, but it was still legs.
The Sprint Spell was fast in a straight line, but short-range.
The Side-Shift Spell was agile, but short-range with a cooldown on top of it.
The Flight Spell worked on any terrain, but was hard to control. Best for crossing obstacles or gaining a height advantage.
Used alone, each had clear limitations. But what if he combined them?