Autumn 1962. Regulus was a year and a half old, Sirius three.
Sirius's side of the nursery had descended into chaos. Toy broomstick parts, biting magical tops, and a box of goblin-made metal puzzles littered the floor.
Regulus's corner, by contrast, remained orderly. A few picture books sat arranged on a deep blue carpet alongside a motionless stuffed Kneazle. It used to move, until Sirius broke it.
That afternoon, Kreacher was using magic to clean the windows, but his ears were pricked to catch any sounds from the young masters, his eyes watching from their corners.
Sirius had just brought a miniature broom from Orion's study. It was a scale model of a real broom, a teaching tool used to demonstrate the principles of flying charms.
"Watch this, Regulus!" Sirius called loudly for his brother's attention. "This is a broomstick! A real wizard's broomstick! I can make it float!"
He placed the broom on the carpet, stepped back two paces, took a deep breath. His little face began turning red from the effort.
"Up!" he shouted, his hands making upward lifting motions to match.
The broom twitched slightly. One end lifted about five degrees, then fell back down.
"Up! Up!" Sirius tried twice more. This time the broom rolled half a turn in place. It didn't fly.
Kreacher held his breath. He knew this broom had been charmed with restrictions. Only someone who understood that levitation required imagining the weight disappearing could activate it.
This was Orion's tool for testing a child's magical comprehension. Sirius thought he'd stolen it, but that was precisely Orion's intention.
Sirius clearly hadn't grasped it yet.
"Why won't it work?" He huffed and kicked the carpet. "Father can make it fly!"
But then Regulus moved. He climbed up from his carpet, moving faster than usual, walked over to the broom, and sat down with a thump.
Sirius looked at him and pouted dismissively. "You want to try? You can't even talk yet."
Regulus ignored him. He simply extended his right index finger, holding it above the broom.
Then his fingertip pressed downward, and the broom slowly rose, reaching the level of Regulus's eyes before hovering motionless in the air.
Sirius's mouth fell open. The cloth Kreacher was controlling dropped to the floor.
With a gentle press of Regulus's finger, the broom slowly descended, landing back in its original position, not a fraction off.
Sirius stammered, "How... how did you..."
He was completely baffled. Why could his brother do what he couldn't?
Regulus turned his head and spoke his first complete sentence in a young but clear voice. "Think, then do."
"Think what?" Sirius asked instinctively.
"Think it's light," Regulus pointed at the broom. "Don't think it's heavy."
"But it is heavy!"
"Think it's not."
"How is that possible?"
Regulus tilted his head, as if considering how to explain. Then he patted the carpet beside him and said to Sirius, "Sit."
Sirius obediently sat down, completely overlooking the fact that his brother could suddenly speak so clearly.
Regulus picked up a leaf that had drifted in through the window and placed it in his palm. "It's light."
"Right."
"Think it's heavy."
Sirius stared at the leaf, trying hard to imagine it was as heavy as a stone.
Nothing happened.
"Wrong." Regulus spoke as if he knew exactly what Sirius was thinking. "Don't think 'it's as heavy as something else.' Forget that it's light. Then it becomes heavy."
Sirius frowned. This was too abstract. He'd never imagined things this way before. He scratched his head, his face full of confusion.
Regulus wobbled to his feet and returned to his corner, leaving Sirius to wrestle with the concept alone.
He'd completed his teaching. But this kind of understanding was still too early for a three-and-a-half-year-old Sirius.
For him, though, it was different. When it came to comprehension and insight, age had never been a limitation.
After dinner, Orion summoned Kreacher to his study.
"That teaching broom," Orion sat behind his desk, brow furrowed. "Regulus made it levitate?"
"Yes... yes, Master." Kreacher nervously wrung his tea towel. "Young Master Regulus made it fly. One foot up. Very steady."
"He spoke?"
"A few words." Kreacher repeated what Regulus had said to Sirius.
After listening, Orion remained silent for a long time. The ancestral portraits on the study walls pretended to look elsewhere, but their ears were all pricked.
"From now on," Orion finally said, "whatever Regulus wants to do, as long as it's not dangerous, let him do it. But watch him. Record everything. Report to me every day before dinner."
"Yes, Master!"
...
December 1963. Number 12 Grimmauld Place was preparing for Christmas.
Sirius Black had just turned four a month ago and was at the "I'm the greatest in the world" stage.
He stood in the center of the drawing room, hands on his hips, making proclamations to a half-decorated Christmas tree. "I'm going to make the bells on the tree ring by themselves!"
Walburga leaned out from the second floor. "Sirius, don't make trouble. Kreacher, hang the silver baubles higher. Last year they were too low. Andromeda nearly hit her head."
"Yes, Mistress." Kreacher extended his spindly fingers to move the baubles higher.
Regulus sat on the thick carpet by the fireplace. At that moment, he was as quiet as a potted fern in the corner.
The soul from another world had been in this body for three years now. He'd long since accepted reality. This was a magical world. He was Regulus Black, the tragic character who died young in the original story.
But he didn't intend to repeat that tragedy. He had bigger goals. The stars, the cosmos, those realms the original story never touched.
As for Sirius?
Let him be, Regulus thought. He'll become a champion of justice in the end anyway, a hero fighting against Voldemort.
As long as I'm alive, the Black family's resources are my stepping stone. No need to compete with a four-year-old.
"Regulus! Watch this!" Sirius's voice pulled him back to reality.
Sirius took a deep breath, staring at a golden bell at the top of the tree. Once again, he turned his little face red, his hands making grasping motions.
Magic began to surge.
"Move!" Sirius shouted.
Regulus's sensitivity to magic was unusually acute, like having an extra sensory system. He could see Sirius's magic surging, and it was about to spiral out of control.
Bang!
The entire Christmas tree began shaking violently.
The star ornament on top fell off and crashed onto Kreacher's head. Candy canes hanging from the branches clattered against each other. Glass baubles chimed.
A string of color-changing magical lights at the top suddenly began flashing wildly, the frequency like an epileptic seizure.
"Stop! Stop!" Walburga rushed down the stairs.
But it was too late.
Sirius had frightened himself with his own magic. He wanted to stop, but he couldn't. Panic filled the young child's face as he waved his hands uselessly, which only made his magical output more unstable.
Boom!
Three floor-to-ceiling windows on the east side of the drawing room shattered simultaneously.
Glass shards sprayed outward, fortunately hitting the protective charms and slowing to a halt. Otherwise, the entire street outside would have suffered.
The chandelier swung wildly, its crystal pendants clanging together with a piercing noise.
"Ah!"
The portraits shrieked collectively. Phineas Nigellus bellowed the loudest. "Barbarian! The Blacks have truly fallen!"
Walburga raised her wand and struck Sirius with a powerful calming charm.
He staggered backward, falling to sit on the floor, staring blankly at his hands.
Walburga's expression was remarkable. First anger, but then something closer to pride.
"Plenty of magical power," her tone was somewhat strange. "But the wrong direction. Next time aim at something useless, like those ugly vases your father collects."
Sirius blinked, not understanding. He'd expected to be scolded.
Regulus closed his book.
This was the trouble with wizard children, he sighed. Magic fluctuating with emotions, like a pressure cooker without a safety valve, ready to explode at any moment.
Kreacher began cleaning up the mess. Walburga gave Sirius a complicated look and turned to head back upstairs.
Sirius sat on the carpet, looking at his hands, then at the shattered windows, and finally at Regulus.
"I did it," he said quietly.
Regulus nodded. "Impressive."