September 1, 1972. 10:47 AM. Regulus Black stopped in front of the barrier between platforms 9 and 10 at King's Cross Station.
The eleven-year-old was slender, dressed in perfectly pressed dark green robes, the Black family crest brooch pinned to his collar.
His hair was pure black with the signature slight curl of the Black family, and his grey eyes calmly scanned the surroundings.
In his left hand, he carried a brand-new dragon-hide trunk, Walburga had insisted on the most expensive one. In his right hand, he held a cage containing a snowy owl.
The owl in the cage stood quietly, its amber eyes observing the surroundings through the bars. Unlike other owls that flapped their wings anxiously, it only occasionally turned its head.
Regulus took a deep breath.
Through this wall lay another world, a world he had read about in books for ten years and was now about to step into personally.
He stepped forward. The sensation was like passing through a warm mist, and then the sound washed over him.
It was a clamor full of vitality and chaos: the hooting of owls weaving into a discordant chorus, the dissatisfied mewling of cats in baskets.
Screams triggered by toads escaping from unfastened pockets, last-minute instructions from parents, and the shouts of children so excited their voices cracked.
Platform 9¾.
The Hogwarts Express lay on the tracks like a crimson beast, its engine spewing white steam that condensed into rolling clouds under the platform roof.
Students surged toward the train doors like a tide, their colorful robes merging into flowing blocks of color.
Regulus stood still, his gaze calmly sweeping across the platform.
He saw the Potters. Charlus and Euphemia Potter stood not far away, wearing the gentle smiles of ordinary parents sending their child to school.
Four people were gathered around them.
James Potter stood at the front, his brown hair messy as if just swept by a hurricane, his glasses perched crookedly on his nose.
He was waving his arms, demonstrating some exaggerated movement to a thin boy carrying a battered trunk, Remus Lupin.
Peter Pettigrew stood half a step behind James, short, round-faced, his eyes darting around ceaselessly.
Sirius Black leaned against his luggage.
At thirteen, he had grown taller since last summer, his shoulders beginning to show the definition of a young man.
He wore those Muggle jeans Walburga loathed, washed until pale and worn at the knees. On top, he wore a plain dark shirt, with a Gryffindor robe draped loosely over it.
The robe had clearly been altered, the silver trim at the collar had been dyed gold and red, and there were traces of an embroidered lion on the cuffs.
James said something, and Sirius threw his head back and laughed, a truly relaxed laugh that came from deep within his chest. One hand rested on Remus's shoulder, the other gesturing.
Then his gaze swept across the platform and landed on Regulus. The laughter naturally subsided.
He didn't look away, but neither did he nod or signal. He just watched quietly, across a distance of twenty feet, through the noisy crowd.
Then James saw him too.
"Hey!" James shouted, his voice clear even amidst the platform's din. "Look who it is! The little snake of the Black family is here early to get used to the environment?"
The shout attracted the attention of other students and parents, for a moment, many eyes turned toward him.
Sirius placed a hand on James's shoulder. The movement was light, but James immediately shut his mouth. Sirius said nothing, only shook his head, then turned, opened a carriage door, and was the first to board the train.
James followed, with Remus and Peter close behind. Before boarding, James looked back at Regulus once more, a glint of mixed curiosity and hostility in his eyes.
Regulus picked up his trunk and walked toward the middle of the train. James Potter was not worth caring about.
The interior of the Hogwarts Express was more spacious than it appeared from the outside, a classic application of the Undetectable Extension Charm.
The corridor was lined with deep red carpet. Sliding doors lined both sides, most already closed, with sounds of conversation and laughter emanating from within.
Regulus walked quietly through the corridor.
Passing the third compartment, the door was open. He glimpsed the scene inside: James had taken off his jacket and was trying to stick a Chocolate Frog card to the ceiling.
Peter was fiddling with luggage, head down. Remus sat by the window, holding a battered copy of A History of Magic.
Sirius sat opposite him, legs propped up on the empty seat, playing with a model Golden Snitch, heaven knows where he got it.
Sirius looked up, his gaze passing through the open door and meeting Regulus's.
Then Sirius looked down and continued to fiddle with the Snitch, as if he had seen nothing.
Regulus continued walking forward.
Passing a few more compartments, most of which were full, he saw two people near the seventh compartment.
A red-haired girl with green eyes and faint freckles on her face. She wore plain black robes, washed very clean, with a simple silver brooch pinned to the collar. Lily Evans, second year.
Beside her was a black-haired boy with greasy hair and sallow skin. His robes were obviously second-hand and altered to fit, with signs of wear on the cuffs. Severus Snape, also second year.
The two were talking in low voices. Snape leaned forward as he spoke, speaking quickly, his fingers occasionally tracing trajectories in the air. Lily listened intently, nodding occasionally.
When Regulus passed by, Snape looked up and glanced at him.
Then he saw the trunk in Regulus's hand, the snowy owl in the cage, and the well-tailored, expensive dark green traveling cloak Regulus wore.
His lips pursed slightly, and a mix of hostility and wariness flashed in his eyes.
Then he looked away and continued speaking to Lily.
Regulus walked to the ninth compartment, which was empty.
He put his trunk on the luggage rack and the owl cage under the opposite seat. After sitting down, he took out a notebook from his robes.
He found the most recent page he had written on: The Relationship between Ancient Rune Variants and Magical Flow Efficiency.
Below it was a series of complex symbols, formulas, and charts. Some were standard ancient runes, but most were variants he had improved upon, simplifying the strokes and optimizing the paths of magical conduction.
He took out a quill, dipped it in ink, and began to record his thoughts from the previous night.
The train left the London suburbs. The scenery outside the window changed from dense buildings to scattered farmhouses and then to rolling fields. The sky was gloomy, clouds hanging low as if it were about to rain.
Suddenly, the compartment door was yanked open, hitting the wall with a dull thud.
Regulus looked up after finishing a complex curve.
Actually, he didn't need to look; he had sensed who it was while the person was still outside.
"Look who it is!" James Potter's voice was full of performative exaggeration. "The little young master of the Black family, studying Dark Arts all alone in here?"
Regulus didn't react, just quietly watched his performance.
Although James Potter was a second-year, to Regulus, he was no different from a toddler.
James walked into the compartment, Remus and Peter following behind. Remus looked uneasy, while Peter nervously gripped the doorframe, looking ready to flee at any moment.
"I'm talking to you!" James walked up to Regulus, leaning down to stare at him, his tone aggressive. "I heard you always bully Sirius at home? Pretending to be the good child and stealing all the attention?"
"James," Remus's voice was very low. "Don't do this."
"Don't do what?" James straightened up, his hand already reaching for the wand in his robe pocket.
Regulus just found it amusing. He wondered how Sirius had described him to his friends, claiming that he bullied Sirius.
"James!"
Sirius's voice came from the corridor. He appeared at the doorway, his breathing slightly uneven.
He said to James, "I told you, don't come."
"I was just looking!" James was unconvinced. "It's not like he's going to eat anyone-"
Just then, two more people ran over.
It was Lily Evans and Severus Snape.
Snape glanced at the situation inside the compartment, a corner of his mouth curling into a mocking arc. "Quite lively. Potter bullying first-years again?"
James spun around violently. "None of your business, Snivellus!"
Then he saw Lily Evans behind him, and his tone became even nastier. "You again, meddlesome Evans."
Snape's face instantly darkened, and his hand also reached for his wand.
Lily pulled him back. "Severus, don't!"
But James was faster. "Expelliarmus!"
A jet of red light shot toward Snape.
The compartment was narrow, and the two were less than ten feet apart. The spell reached Snape almost instantly.
A wand slid automatically into Regulus's left hand. He waved it only slightly, effortlessly, without any intense movement.
But the spell stopped. It was frozen in mid-air.
The red light manifested in the air. The Disarming Charm now looked like a glowing red ribbon, one end connected to the tip of James's wand, the other end suspended half a foot in front of Snape's chest, motionless.
The entire compartment fell into a dead silence.