Deep in the Forbidden Forest, near Aragog's lair, Regulus appeared with a crack of Apparition.
Baruk immediately came rushing out of the hollow.
The two-meter Acromantula skidded to a stop in front of him, all eight legs digging into the dirt as its chelicerae rattled excitedly. Regulus patted its head and climbed onto its carapace.
Baruk took off.
The forest blurred around them as it raced between the trees, but this time Regulus barely felt the usual jolting. Looking down, he quickly discovered why.
Baruk had woven dense spider silk around the joints of its legs, connecting them into a flexible mesh. Each landing compressed the silk and absorbed the impact, then released the stored energy as the leg lifted. The eight legs had also been divided into two coordinated groups, keeping the carapace almost perfectly level.
The Acromantula had essentially built itself a suspension system.
It made Baruk faster and quieter while also giving its rider a remarkably smooth ride.
"Since when were you this clever?"
Baruk clicked its chelicerae proudly and sped up.
After a while, they reached a clearing beneath a break in the canopy. Regulus stopped Baruk and conjured a floating orb of light overhead. The sudden brightness sent insects scattering through the undergrowth.
Then he condensed the moisture in the air into a smooth mirror.
Tonight, he had work to do.
He stared at his reflection.
Black hair. Grey eyes. Delicate features. The unmistakable appearance of a member of the Black family.
That face couldn't accompany him outside Hogwarts.
Dumbledore's activities were becoming increasingly connected to the growing conflict with Voldemort. The Order of the Phoenix was expanding, allies and informants were moving around constantly, and the Death Eaters were becoming increasingly active. If Regulus were seen openly associating with Dumbledore, there was little chance his identity would remain secret for long.
The magical world was already full of cracks. Both sides relied on chains of trust, and both sides were vulnerable to betrayal. Dumbledore had the ability to see through people but chose not to invade their minds. Voldemort had no such restraint, yet fear could only force obedience, not loyalty.
Neither method was perfect.
So Regulus needed another identity.
His lips moved silently.
The black of his hair gradually faded into silver-white. He lengthened it past his shoulders and roughened its texture, transforming the neat, aristocratic hair of a Black into something wilder.
His grey eyes shifted toward amber-gold, the pupils narrowing into vertical slits.
His cheekbones hardened, his jaw broadened, his brow became more pronounced, and his nose straightened. His height increased to a little over 180 centimeters, his shoulders widened, and his body became that of a solid young man rather than a slender teenager.
The person in the mirror no longer looked remotely like Regulus Black.
He looked like a young wizard who had spent years on the road, exposed to the elements and accustomed to fighting.
That was exactly what Regulus wanted.
But appearance alone wasn't enough.
Anyone with strong Magic Perception could recognize the texture of another wizard's magic. Regulus's own magic was calm, precise, and tightly controlled. It was another unmistakable signature.
He needed to change that too.
Closing his eyes, he drew on the image of Betelgeuse, the unstable red supergiant he had used as an anchor for explosive power during his Star Guided Meditation.
A trace of that violent, expanding energy seeped into his magic.
Instead of remaining compressed inside his body, his magic began leaking outward, forming a hot, restless pressure around his skin. It felt unstable and aggressive, as though it might explode without warning.
The transformation was complete.
Different face. Different magic.
Now he needed a different way to fight.
His usual style relied on distance and precise control, gradually restricting an opponent's options until there was nowhere left to escape.
That wouldn't suit this identity.
The new persona would fight at close range.
Regulus jumped down and lowered himself into a fighting stance.
Swiftness Spell.
Sprint Spell.
His body launched forward.
He crossed the clearing almost instantly, changed direction, and slammed a spell into a dead tree at point-blank range. The volatile magic exploded through the trunk, tearing it apart.
He continued moving.
A sharp turn. A low slide. A push off the ground. Another burst of magic smashed into a boulder and blasted a crater into its surface.
He kept experimenting, mixing sudden acceleration with abrupt changes of direction and close-range detonations. Sometimes he approached directly. Sometimes he slowed, circled, and attacked from the side. Sometimes he suppressed a target from a distance before rushing in to finish it.
The pressure radiating from his body made the style even more dangerous at close range.
Fast, aggressive and overwhelming.
Nothing like Regulus Black.
By the time he stopped, the clearing was covered in scorch marks, broken branches, shattered stone, and churned earth.
Regulus looked around and nodded.
That was enough.
Appearance, magical signature, fighting style.
Three separate layers of disguise.
Unless someone possessed some extraordinarily obscure method of seeing through all three, connecting this silver-haired, amber-eyed young wizard to Regulus Black would be extremely difficult.
And if someone did manage to discover the truth, that was another problem entirely.
He had methods for dealing with people who knew too much.
Regulus dismissed the transformation.
The unfamiliar young man vanished.
The quiet black-haired boy stood in the mirror again.
He dispelled the mirror and the light orb, leaving the clearing beneath the moonlight.
Baruk waited at the edge of the clearing, watching him.
Regulus walked over and patted its carapace.
The Acromantula rubbed its head against his shoulder.
It still wasn't coming with him.
Convincing Baruk to accept that had taken days, along with promises of a trip beneath the Black Lake, larger portions of dragon meat, more time in the Forbidden Forest, and an absolute guarantee that it would accompany him next time.
Baruk finally clicked its chelicerae twice.
Then it backed away, settled into the leaves, and rested its head on its front legs, watching him with eight glimmering eyes.
Regulus gave it one last pat.
"I'll be back."
He Apparated.
At the edge of the forest, Hogwarts stood beneath the night sky, its windows glowing softly in the darkness.
Regulus pulled his robe closed and flew toward the castle.