Lily gathered her stack of books again, then hesitated and set them back down.
"Actually, I'm looking for sources for a Potions essay," she said. "Professor Slughorn assigned a review on how moonstone works in calming draughts. He wants at least three primary references."
She stared at the pile with a troubled expression. "But I don't know how to organize it. All these books say roughly the same thing, but not quite."
Regulus glanced at her. He knew young witches and wizards had never been taught how to write this kind of paper.
"How do you usually write essays?" he asked.
"Well…" Lily hesitated. "I copy what the books say and add my own understanding?"
Regulus pulled out a chair and gestured for her to sit with him.
"There's a structured way of writing papers used in Muggle universities," he said.
The moment she heard Muggle universities, Lily's eyes lit up.
"First," Regulus continued, "don't start writing right away. Read through all your materials. Note down every useful point and mark the source."
Lily blinked, listening intently.
Regulus tore a blank sheet of parchment from his notebook and ripped it into small strips.
"For example," he said, writing as he spoke, "Moonstone's lunar magic can neutralize residual agitation from nightmare grass. Moonlight and Potions, page 147."
In the corner, he wrote "Source One."
"Now you have one discrete piece of information. Once you've gathered enough, you sort them. Properties. Preparation methods. Side effects."
Lily's eyes widened. "And then?"
"Then you look for the relationships between them." Regulus tapped his wand lightly, and the parchment slips floated into the air.
"Say Book A says moonstone should be ground into powder. Book B insists it must be sliced. Book C uses it whole, steeped intact.
At that point, you ask why. Different recipes? Different schools of thought? Or maybe the authors studied moonstone from different regions?"
The slips rearranged themselves in midair.
"When you find the reason for the differences, your essay gains depth. Finally, you connect everything with your own logic. 'Considering factor X, Author A's view applies better in situation Y, while Author B's method is superior under condition Z. Therefore, a combined recommendation would be…'"
Lily was completely absorbed. She pulled out her own parchment and quill, scribbling the steps down as fast as she could.
"Skim, source, categorize, find connections, build logic…" She looked up, thrilled. "This is amazing. Can I tell other people? My friends are struggling with their essays too!"
Regulus nodded. "You can. Just don't say I taught you."
She stopped writing and looked at him, confused. "Why not?"
"Because I'm a Slytherin, and you're a Gryffindor," Regulus said calmly.
"Some boundaries don't need to be crossed deliberately. And there's no need to provoke anything. If your friends ask, say you saw it in a Muggle library."
A Slytherin sharing Muggle methods was taboo among pure-blood circles, especially in the current climate.
But he believed Lily would keep the secret. She understood the importance of boundaries.
It was also a test.
Whether she could keep a promise mattered.
After a moment of thought, Lily understood his meaning. As a pure-blood Slytherin, he shouldn't be the one to discover, promote, or spread Muggle approaches, even if they worked.
She nodded firmly. "I understand. Thank you, Black."
"You're welcome."
Lily packed up her things and headed off. At the end of the shelves, she turned back.
"You know," she said, "if you were in Gryffindor, we might've become very good friends."
Regulus looked up at her earnest expression.
His voice was quiet. "Friends aren't divided by Houses, Miss Evans."
Lily smiled, bright as sunlight breaking through clouds.
"Then… goodbye, Regulus."
"Goodbye, Lily."
The red-haired girl disappeared between the shelves. Regulus stayed seated, knowing someone else would come.
Five minutes later, a cold voice emerged from the shadows.
"Stay away from her."
Severus Snape stepped out from between two shelves, his black robes nearly blending into the darkness.
He looked paler than usual, lips pressed into a thin line. Something restrained and furious churned in his dark eyes.
Regulus stopped what he was doing and met his gaze calmly. "Snape. Can I help you?"
"I said, stay away from Lily," Snape hissed, his voice low and sharp, like a snake tasting the air. "Your tricks are obvious. Pretending to be gentle. Pretending to be different. All to gain her trust, and then—"
"And then what?" Regulus cut in. "Use her? Hurt her?"
Snape took a step forward, fingers tightening at his sleeve. "You think you're better than the rest of them? You think I don't see what you're doing?"
Regulus let out a quiet breath. "Snape, you were watching the whole time, weren't you? Watching Lily talk to me. Watching her smile. Watching her leave. And then you came out to warn me."
He looked straight at him. "Do you think that's protecting her? Or is it that you can't stand seeing her show kindness to anyone but you?"
Snape's face twisted. "You—"
"Let me finish." Regulus lifted a hand, small and controlled. "You're angry not because I might hurt Lily. You know I won't. At least not now.
You're angry because Lily chose to talk to me. Because she smiled at me. Because she looked like she was willing to trust a Slytherin who wasn't you."
He leaned back slightly. "You want to be the only wizard she trusts. The special one. The one who understands her completely."
Snape's breathing grew ragged. His fingers trembled.
The truth had landed.
Regulus shook his head, his tone cooling. "Today she talks to me. Tomorrow she might brew potions with James Potter."
At the name, Snape's pupils shrank. His fingers almost curled around his wand.
"See?" Regulus said quietly. "I only said his name, and you lost control."
"I'll give you some advice, Snape. If you truly care about Lily, don't try to control who she talks to or befriends. All that does is push her farther away.
Let her choose to stay by your side. Don't force it by driving everyone else off."
Snape stood rigid, his body taut beneath the robes. After several seconds, he finally spoke.
"What would you know… a pure-blood heir like you could never understand—"
"I understand more than you think," Regulus interrupted, meeting his eyes. "I understand pure-blood arrogance. I understand the struggle of half-bloods. I understand the isolation of Muggle-borns.
None of that excuses what you're doing."
He stood and walked past Snape without another glance.
"Warning me?" he said lightly.
He retrieved Astrological Meditation and headed toward Madam Pince's desk, leaving Snape alone in the shadows.
As he walked, Regulus reflected that Snape was a contradiction. Brilliant talent, trapped by inferiority and possessiveness. Craving power. Drawn to darkness.
In the original story, he only woke up after losing Lily, when it was already too late.
Today's words might not sink in. If Snape was smart enough, he would start to reflect. If not, then at least he now knew Regulus wasn't his enemy.
The irony was that Snape's fixation on Lily was his greatest weakness. Voldemort would exploit it. Dumbledore would too.
Perhaps when everyone else tried to use that obsession, the one person who didn't would gain something unexpected.
And speaking of Snape inevitably led to James Potter.
In Regulus's view, Lily's so-called destined match was little more than a disposable character.
A schoolyard bully who happened to repent later, join the "right" side, and was then celebrated as a hero.
Rewarded with love. With friendship. With family. With posthumous honor.
The world could be deeply ironic. Good and evil, hero and villain, were often judged not by what you'd done, but by where you stood at the end.
Snape wasn't a good man. Potter was no better. From some angles, Potter was worse.
Regulus let the thought go. Since this world embraced redemption arcs, there was no need to dwell on it.
Madam Pince examined the book. "Astrological Meditation. Obscure. Two-week loan period."
"That's enough," Regulus said, signing his name.
When he left the library, torches were already lit along the castle corridors, their flickering light stretching long shadows across the stone walls.