Nine thirty on Saturday morning. Regulus knocked twice on McGonagall's office door.
"Come in."
He pushed the door open and took his first step. The transformation started as he crossed the threshold.
Two steps, and he'd become a different person head to toe. The pressure came into the room with him.
McGonagall sat behind her desk, quill stopped in midair.
One eyebrow lifted, and the light in her eyes flared up like something had caught fire. It was visible even through her glasses.
Then she pushed it back down, pressed her lips together, and returned to her usual severity.
Minerva McGonagall. Transfiguration master, Head of Gryffindor, the strictest professor at Hogwarts.
A textbook Gryffindor.
She'd made preparations like this herself when she was young. During the Grindelwald years, following Dumbledore, walking plenty of roads she should and shouldn't have walked.
She'd seen real darkness on a battlefield, and seen the light that struggled up out of it.
Back then she'd stood in some room too, transfiguring her robes in front of a mirror into something better suited for action, wand in hand, thinking about what came next.
Her eyes had held this same light. Knowing she was walking into an adventure, and being ready for it.
She recognized that quality. She just hadn't seen it in a very long time.
She didn't say anything complimentary. She only let her gaze linger on him a moment longer, something restrained in the fine lines at the corners of her eyes.
Then she stood up and came around the desk to him, walking a little faster than usual, her robes swirling around her ankles.
She raised her wand. "Stand still."
Regulus had been standing still the whole time.
He was probably the student who understood Professor McGonagall best. There was far more to her than the strict exterior.
He could see the excitement she couldn't quite hide.
Her wand touched his shoulder and she began casting. Permanent Transfiguration.
His robe, already transfigured once, started changing the moment the wand came down.
The fabric tightened. The color sank to a dark grey verging on black. The hem drew up, excess material vanished, the loose sections were cut away, and a fitted line emerged.
A short dark grey waistcoat, high-collared and sleeveless, with reinforcing patterns woven into the shoulders and chest to spread impact.
Underneath, a dark narrow-sleeved shirt with tightened cuffs that didn't restrict his wrists. A wide leather belt with a concealed clasp.
Straight dark trousers tucked into the boots. Short dragonhide boots, light, silent on the floor.
The whole thing was clean, without an inch of spare fabric, built for fast movement and close combat.
McGonagall lowered her wand and stepped back to look him over.
Regulus raised his arms, twisted at the waist, kicked out twice to get a feel for it.
Better than what he'd done himself. The clothes fit perfectly, no drag at all, and nothing pulled tight when he reached.
Clearly she had a lot of experience with this. She'd spent time on a battlefield when she was young, so this probably wasn't her first time altering someone's combat gear.
"Thank you, Professor."
McGonagall made a small sound of acknowledgment. Her eyes went from the woven patterns at his shoulder down to his belt buckle and back to his face.
The corner of her mouth curved up a fraction. It was small and fast, and she pulled it back almost immediately.
She returned to her desk, sat down, and waved a hand for him to continue.
Regulus took the phoenix tail feather out of his inner pocket.
Almost four months since he'd gotten it before Christmas, and the magic in it was still full. He could feel a faint pulse, the same as the day it was pulled.
He gripped it, closed his eyes, and thought of Fawkes.
A moment later the air in the office started to heat up.
The temperature climbed fast in a very small area. The air warped slightly, then the warping spread, light started bending, and every outline blurred.
Then golden flame burst open out of nothing, blooming silently in midair.
A clear cry came with it, high and far-carrying, piercing, ringing out from the center of the fire and bouncing off the stone walls.
The edges of the flame were pure gold, shading inward to orange-red, with a deep red core.
Warm, bright, burning nothing. A gentle heat filled the air, something like the smell of sunlight.
The center of the fire drew in, and the outline of a wing unfolded from the gold.
The tip first, then the whole wing, the feather edges gilded by the flame, sparks scattering off the ends.
Fawkes flew out of the center, tail trailing, gold and red feathers burning in the fading light.
He landed on the edge of McGonagall's desk, claws hooked firmly over the rim, wings folded, head up, black eyes sweeping the room.
The flames faded, leaving only warmth behind and a faint golden glow around where he'd landed.
Regulus's spatial perception had latched on the instant the fire bloomed.
A small region in the center of the office had stopped existing. Where the phoenix fire had burned, the space itself was gone, edges clean and smooth, leaving a hole that was already closing fast.
The gap was there, exactly as he'd expected.
He didn't hesitate. Straight to work.
But the Betelgeuse image definitely wouldn't do.
If he used Betelgeuse and it actually worked, this whole area would take on a scorching, restless undertone.
McGonagall's office was on the ground floor, the busiest part of the castle for students, surrounded by classrooms and corridors, close to the Great Hall. People walked past several times a day.
Give a crowd of already energetic teenagers a dose of Betelgeuse agitation and they'd all be inexplicably keyed up, unable to sit still in class, unable to sleep at night. It was spring. Things would happen.
The professor would come after him first.
Bellatrix was the right choice. A guardian image, gentle, protective, and even if it failed the effect on the surroundings would be small.
If it worked, her office would carry a reassuring atmosphere from then on. Any student called in for a talking-to would feel a little less nervous walking through the door.
Call it castle improvement. A good deed.
In the instant the flames died and before the hole in space had closed, he pushed the guardian will of Bellatrix into it.
His amber-gold slit pupils filled with blue-white light, welling up from deep in the pupil, constant and steady, both eyes glowing in a way no human's should.
There was no time for fine control. This one was brute force. The window was a fraction of a second, so the blue-white light condensed into a torrent of will and poured into the vanishing hole all at once.
Then the space closed. Far too fast.
The castle's space snapped back almost the moment the phoenix fire faded, filling the hole in, quick enough that his will was squeezed out the instant it reached in.
The air in the office trembled briefly.
The window glass gave a low hum. The parchment on the desk rustled, the quill wobbled in its stand, and the fire in the hearth leaned to one side and sprang back.
In the painting on the wall, a tabby cat poked half its head out past the edge of the canvas, took a look, and pulled back in.
The rejected guardian will broke into fragments. A few blue-white wisps of magic drifted slowly downward, still faintly stirring the castle's newly restored spatial structure.
McGonagall sighed.
She'd probably seen this coming from the moment Regulus asked to borrow her office. This boy was never going to use a phoenix feather for nothing but transport.
She didn't scold him. She just acted.
A flick of her wand and magic poured out, wrapping the blue-white wisps in the air, gathering them, pulling them together, then dissolving them cleanly.
Then she turned to the patch of space still trembling in the office.
Her magic seeped into the grain of the space, gentle and fine, smoothing over the disturbed folds layer by layer.
The precision of it was hard to believe, even watching from beside her.
Every thread of magic followed the run of the spatial structure. No forcing, just going with it, brushing lightly past, letting the folds loosen on their own, letting the castle's will settle back into the area.
Before long the trembling stopped and the office was back to normal.
It hadn't worked, and he'd nearly caused a scene. The castle still didn't like him.
Regulus let his outside match his inside.
He shrugged and pulled the corner of his mouth into a fair enough expression.
With his current face, it actually looked natural.
Failed was failed. It had been a spur of the moment idea, and trying cost him nothing.
Not a total loss, either.
Both his spatial perception and his magic perception had caught everything McGonagall did.
The path her magic took into the grain of the space. The precision of every thread following the structure's direction. And that method of going with it, letting the castle's will quiet down on its own.
His own understanding of the castle's will was still stuck at the castle doesn't like me.
He'd run into walls plenty of times. He knew the castle had a will, and he knew it refused him. What he hadn't worked out was how to make it accept him after a refusal.
The professor's grasp of the castle's will went far beyond what he'd expected.
He could perceive spatial structure and build folds and anchors in it. But what she'd just done, performing a soothing operation on the castle's will, was beyond him.
Was it a matter of position? Did you have to be Headmaster? Would Head of House do?
Dumbledore could definitely do it. The Headmaster ought to be the master the castle's will recognized.
A Head of House probably had some level of permission too, being part of the castle's administrative system.
An ordinary professor, probably not.
So to get on good terms with the castle, he'd have to land a title first?
McGonagall finished and turned to look at him.
She didn't say anything. She just watched him through those square glasses, a trace of exasperation in her eyes, lips slightly pressed, then let out a breath through her nose.
"Next time, warn me first."
Regulus wasn't the least bit embarrassed. He grinned, silver-white hair shifting on his shoulders. "All right."
Fawkes had stayed perched on the edge of the desk through all of it.
From the spatial experiment to the castle's reaction to McGonagall's cleanup, he hadn't moved. His gold and red head was tilted, black eyes fixed on them.
Phoenixes see souls.
Silver-white hair, amber slit pupils, a burning magical field. A new face, new clothes, a new temperature to his magic. To a phoenix, all of it was transparent.
Whatever color your hair is, whatever shape your eyes are, the soul is the same soul. So you're still you.
Fawkes tilted his head and gave him a glance.
Then he turned away, bent down, and preened the feathers on his chest, running his gold-red beak through them a few times. When he finished he shook out his wings and folded them.
Not a single extra gesture.
The noble phoenix wasn't interested in his disguise, and wasn't interested in the mess he'd just made either.
Regulus walked over to him.
This bird had never once been affectionate toward him.
Last time in the Headmaster's office, he'd summoned his Starlight Kite and let the phoenix get a good look before Fawkes would hand over a tail feather.
That had been for the Patronus's sake. No Patronus now, so no attention.
He glanced back at McGonagall.
She stood behind her desk, her expression severe again. "Don't cause Albus too much trouble."
Regulus's mouth twitched. "I'll try."
He held out his hand, and Fawkes lifted a claw onto his wrist.
The phoenix spread his wings, and golden flame burst outward again from the center of his body, swallowing both their outlines.
The fire drew in, faded, and the office was empty.
Two shallow claw marks were left on the edge of the desk.