Another full moon.
Regulus stood atop the Astronomy Tower.
A month and a half into the term, and he'd finally confirmed one thing: inside Hogwarts, fusing his Patronus into spatial magic wasn't going to work.
He'd lost count of the attempts in the Room of Requirement.
He'd drawn the Patronus out from his mental landscape and tried weaving it into the fabric of space itself.
Space ignored him. As though it couldn't even perceive his intent.
He'd switched approaches. If fusion wouldn't work, he'd try seeping it in.
Still nothing.
The theory held up. A Patronus could merge with spells, could bind to them. Why not space?
A Patronus was a boundary. Space was a boundary.
Place the Patronus inside space, let space become an extension of the protection. The logic tracked.
But the Room of Requirement's space wouldn't respond. It didn't refuse, either. It simply gave nothing back.
Regulus thought about it for a long time.
The Room of Requirement was Rowena Ravenclaw's creation. A witch of that caliber leaving behind something impenetrable made perfect sense.
Perhaps the space itself had a will of its own, one he couldn't perceive.
If the Room wouldn't cooperate, he'd try elsewhere.
Up here on the Astronomy Tower, in the night wind of Hogwarts, he'd made just as many attempts.
Same result. Hogwarts's space wouldn't respond either.
No refusal, but this time Regulus sensed something subtle. Like speaking to empty air. Air wouldn't answer.
But this air had an owner.
He stopped trying. This path was closed. At least here.
Someday, somewhere else, it might work. Not at Hogwarts.
He'd set himself several directions this term. Spatial magic was the priority.
Space warp, space anchors, spell warp, spatial transfiguration, spatial network. All progressing steadily.
Merging his Patronus with space was one branch of that work: turning space itself into a means of protection.
Building an absolute barrier from folded space, so attacks couldn't reach him because the distance simply didn't exist.
Folding space to hide himself or his spells, tucked away in another dimension.
Anchoring himself to a fixed point so no attack could dislodge him.
Drawing on his Patronus's nature to establish a cooperative relationship with space, rather than brute dominance.
These concepts represented the frontier where spatial magic shifted from technical manipulation to something more fundamental.
But he was stuck at step one. Hogwarts wouldn't play along.
Regulus looked up at the sky.
The moon hung full and bright against the velvet dark, bleaching a small circle of sky around it to white.
He stared for a long time, thinking nothing, just looking.
Below, several figures appeared on the castle lawn.
He glanced down. James, Sirius, Peter. Out again.
He looked away and let them be.
Staring at the moon, a thought surfaced from nowhere.
Light.
Last term, in Defence Against the Dark Arts, he'd been turning over an idea. Light Source Magic.
Now, standing on the tower's peak with moonlight falling across him, the thought returned.
Could magic manipulate light?
The Lumos charm produced a glowing orb. That wasn't what he wanted. He wanted true control.
Ideas detonated in his mind like fireworks, one after another.
Regulus stood on the tower, watching the moon, his mind full of light.
But it was all so far away.
He couldn't even sense light's magical signature yet, let alone manipulate it.
Maybe it would take reaching the sixth star. Maybe the seventh. Maybe Rigel.
Someday, when he could see what light truly looked like, see the photons themselves, he could begin figuring out how to touch them.
He shook his head, shelved those thoughts, and glanced back toward the lawn.
The figures were still there, creeping toward the Whomping Willow.
Regulus watched for a moment, then looked away.
A full month of waiting, and the gut feeling from last time hadn't returned. Probably just a coincidence. Proved nothing.
Fine. He didn't feel like practicing magic tonight anyway. The Forbidden Forest, then.
He stepped off the tower. Wind rushed up beneath him, flipping his robes overhead, and he cast the Flight Spell, drifting in a lazy, unsteady arc toward the forest.
He touched down in the shallower reaches of the Forbidden Forest.
Quiet surrounded him. Moonlight leaked through gaps in the canopy, cutting the ground into a patchwork of light and shadow.
A herd of Thestrals stood in a clearing not far off.
A few of the closer ones watched him. Their eyes glowed a sickly white, hollow, pupilless.
Regulus stood there and watched them back.
Thestrals. They could cross storms, breach magical barriers, and reportedly even slip through space for brief moments.
He wanted to experience that. Not for research. He just wanted to climb on and fly.
He took a few steps closer. The Thestrals didn't retreat, but they didn't approach either. One raised its head and gave him another look.
Regulus stopped beside it, wondering how to communicate.
He didn't know.
But he knew Thestrals could see death. Only those who had witnessed death could see them.
Maybe that was the foundation for communication.
He reached out and placed a hand on the Thestral's back. It didn't flinch. Let him touch it.
The texture was strange. Not soft. Rough, like old bark, but warm.
Regulus let his magic flow outward in greeting, circulating it gently around the Thestral without any intent behind it.
The Thestral raised its head and looked at him once more.
Then its front legs bent, the hind legs followed, and its whole body sank low, the way a horse does when inviting a rider.
Regulus blinked. No hesitation. He swung himself up.
The next second, four legs drove into the earth. The body pitched forward. Wings snapped open.
He gripped its back. Wind flooded his ears. Trees fell away behind him. The ground shrank.
The Thestral burst through the canopy and climbed into the night sky, accelerating.
Fast.
Far too fast.
Faster than the flight spell by orders of magnitude.
Faster than any broomstick.
Wind sliced across his face like a blade. He considered casting Protego, but couldn't bear to lose the sensation.
The Thestral kept flying.
Over the Forbidden Forest. Over the Black Lake. Over the castle. Moonlight poured down from above, and all of Hogwarts spread out beneath him.
Then the Thestral began warping through space.
One stride, and the world changed. A heartbeat ago he'd been above the castle; now he hovered over an unfamiliar stretch of woodland.
Another stride. Somewhere else entirely.
After several warps, all sense of direction dissolved.
Regulus felt a strange force at work. Space was moving.
Each beat of the Thestral's wings pushed space itself backward, and as space receded, the creature surged forward.
That was how Thestrals traveled.
Before he'd had his fill, the Thestral plunged. It landed in a completely unfamiliar stretch of forest, pitch-dark, nothing recognizable in any direction.
The Thestral touched down, gave a sharp shake, and Regulus tumbled off, stumbling two steps before finding his balance.
It glanced at him, let out a low, rasping cry, beat its wings, and vanished into the night sky.
Regulus stood there, mildly incredulous.
Just dumped him here?
Had he gotten the communication wrong?
He looked around. No idea where he was. The trees were massive, branches dense overhead, moonlight blocked entirely.
Somewhere deep in the Forbidden Forest, probably. But pinpointing the location was impossible.
The Thestral had warped through space several times. Direction was meaningless now.
He cast the Flight Spell and floated up, clearing the treetops, scanning the horizon.
In the distance, a faint glow. The castle, most likely, but so far away he had to squint to confirm.
He dropped back to the ground. Was about to Apparate when another thought struck.
That speed. That freedom. What it had felt like on the Thestral's back. He wanted that again.
Regulus stood in place and began to design.
He needed a shell. Protego could provide it, reshaped from a spherical barrier into a three-dimensional structure.
Propulsion could come from Fiendfyre. Fire was force. It could generate thrust. His magic would serve as fuel.
Control would come from magical perception and manipulation, supplemented by a few extras.
Arresto Momentum, to absorb the shock of high speed, letting his body withstand extreme acceleration.
Silencio, to kill the sound of air friction, keeping his presence hidden.
Regulus began.
He cast Protego first, magic spreading evenly outward from his body. As he poured in more power and shaped it, the barrier's form shifted.
The front stretched and tapered to a sharp point, a streamlined nose that followed aerodynamic instinct.
Both sides extended outward, thinning into a pair of short, subtly curved wings.
The rear contracted inward, narrowing to a gradually tapering cone that flared slightly at the end, a bell-shaped exhaust nozzle.
He hadn't referenced any specific design. Just the basic logic of air resistance: minimize drag. Sharp nose to cut the wind, smooth body, flared tail to leave room for what came next.
Then, propulsion. A thought, and a thread of orange-red Fiendfyre ignited silently at the nozzle.
His will held the flame and temperature controlled. Form stable.
The Fiendfyre burned steady inside the nozzle, expanding, and superheated exhaust roared out from the opening.
Thrust. Transmitted through the magical connection to the shell, and through the shell to Regulus inside.
Not enough. The thrust was too diffuse.
He restructured the magic inside the nozzle, concentrating the burn, tightening the exhaust stream.
Thrust climbed noticeably, but direction still wobbled.
At each wingtip, he shaped two smaller auxiliary nozzles from magic, for balance and steering.
Then he layered on the support charms.
Everything ready. Regulus rose to altitude and fired.
All three nozzles erupted at once. Thrust surged, driving him and the entire shell forward.
The initial speed was gentle, like being pulled by a calm, steady hand.
He fed in more magic. The Fiendfyre burned hotter, the exhaust fiercer.
Thrust climbed. Then climbed again.
Then a savage burst of force detonated and he shot forward, the entire shell catapulting through the air.
Speed spiked to something incomprehensible. The air behind him hit like a wall, split open by the nose cone with a deep, thundering roar that even Silencio couldn't fully suppress.
Slowing Charm locked down hard against the force trying to crush his organs against his spine.
Regulus clenched his jaw, steadied his mind, and kept pushing output higher.
The trees of the Forbidden Forest blurred into grey-green streaks on either side, smeared and elongated, details impossible to resolve.
He abandoned vision entirely. All attention collapsed onto magical perception, scanning ahead like radar while he steered through minute adjustments of power.
Speed kept climbing...
The Protego shell began vibrating at low frequency, shrieking against the hypersonic airflow, its surface rippling like disturbed water.
He knew he'd hit the wall. Approaching the speed of sound. Push harder and the Protego shell risked structural collapse.
He held output steady, maintaining current velocity.
He cut through the dark canopy of the Forbidden Forest, shadows flashing past as night creatures startled and scattered at the edge of his senses.
The sensation was strange and pure.
So fast that every detail vanished. The world reduced to direction, speed, and obstacles ahead that needed dodging.
Minutes later, the castle's silhouette appeared.
He adjusted course toward a clearing at the forest's edge and began tapering his magic. Thrust weakened. Speed bled away.
He decelerated further, shifting from level flight to a shallow glide.
On landing, the shell touched the ground, bounced once, and dissolved into silver motes of light.
Regulus rode the momentum forward several steps before steadying himself.
He stood there gasping, every inch of him screaming.
Muscles trembling. Bones aching. Organs feeling like they'd rearranged themselves. Sweat plastered his hair flat.
But he lifted his head, and the grin spreading across his face was something he couldn't have fought if he'd tried.
He straightened slowly, rolled his neck, worked his shoulders, and started walking toward the castle lights, one step at a time.
That thing was fast. Brutally, savagely, almost insanely fast, with a g-force that bordered on primal violence.
But the feeling?
Incredible.
And he could go faster.