Lily's mouth was halfway open. She'd had a line ready, something about the great and busy Regulus Black gracing the Library with his presence, but it died on her tongue.
She blinked. "How did you know about that?"
"Newspapers." Regulus rested his arms on the table, his tone unchanged. "Does your family still have heating?"
"Yes, we have a fireplace," Lily said, still caught in the brief confusion of how the conversation had veered here. She followed his lead on instinct. "Gas fireplace. Doesn't need electricity."
"But the factory shut down production. My dad only works three days a week now." The words came faster as she went, and somewhere along the way, the pretense of anger evaporated without her noticing. "Three days of work, three days of pay. Mum says it's fine, we have savings, but Dad can't sit still. He paces around the house, anxious."
"What about your sister?" Regulus asked.
"Petunia? Her school's rationing electricity too. They only turn on half the classroom lights. She says the students in the back rows can't read the blackboard, and the teachers can't do anything about it. It's not like you can enlarge chalk writing."
Lily closed the book beside her. "They're thinking about letting school out early, three o'clock, because it gets dark so fast in the winter afternoons without lights..."
"Three o'clock." Regulus raised an eyebrow. "Is she happy about that or not?"
Lily paused, then laughed. "Happy. She keeps saying how are we supposed to sit exams like this, but she's grinning ear to ear."
Regulus watched her laugh, and the corner of his own mouth lifted.
"The house next door to ours, there's an old woman who lives there. Her front steps iced over and she hadn't put salt down. Took a fall. The ambulance said their petrol ration was used up, she'd have to wait in the queue. My dad and Mr. Smith carried her to our car and drove her to hospital."
Her brow creased, her voice turning somber. "Dad says there'll be more of this."
Regulus didn't respond, his gaze warm and steady as she talked through her worries.
"I keep thinking, here I am at Hogwarts, drinking Pumpkin Juice, learning magic, and back home the power's out and I can't do a thing about it. The things I'm learning here..." She drew her wand, glanced at it, and set it on the corner of the table. "Hardly any of it's useful at home. The Trace. You know."
Regulus nodded.
"So I've been thinking," Lily said, looking at him. "You told me to practice magical control. That doesn't need a wand. Doesn't trigger the Trace."
"That's right."
"I practiced." She lowered her hand to her knee, palm open, no wand. Her fingers curled slightly.
The parchment on the table shivered, lifted into the air, folded itself into a paper crane, and drifted back down.
"I thought, if the power really stays out for a long time, at least..." She tilted her head, a shy smile pulling at her lips. "At least I could make the candles float on their own. Like Hogwarts."
Regulus gave an approving nod. "That's good."
"And Mum said if the gas goes too, we'll go to Grandmum's in the countryside. She has a wood-burning stove."
Lily propped her chin on her hand again, her voice a shade quieter. "She said that's how they got through the war years. I asked her which war. She said all of them."
Regulus nodded. "Mrs. Evans is a sensible woman."
"If my mum were a witch, she'd be better at it than me." Lily smiled, a flicker of pride in her eyes. "She said when she was young she worked quality control at a factory. Could spot a defective product at a glance. She said if they put her in charge of some department at the Ministry of Magic, she'd send back every substandard potion that crossed her desk."
Regulus raised an eyebrow. "Slughorn would be nervous."
Lily covered her mouth, laughing, then pointed a stern look at him. "Don't you tell the professor."
"I won't," Regulus said, smiling.
By now, Lily had relaxed completely.
She leaned back in her chair, legs swinging idly under the table, her gaze drifting from Regulus's face to the reflection of the two of them in the dark window glass, then back to the book on the table.
"I forgot to write to you over the holiday," Regulus said. "Sorry about that."
Lily looked up. First blank. Then narrowing. Her mouth opened, closed, and then she laughed before she could stop herself.
She laughed for a while, then fixed him with a glare. "You did that on purpose, didn't you?"
Regulus looked thoroughly confused. "Did what on purpose?"
"The power outage! You led with the power outage, then it was our heating, then Petunia, then the neighbor, you had me talking for twenty minutes!" She jabbed a finger at him, face fighting between outrage and amusement, amusement winning. "And only now you apologize! I've forgotten what I was going to say to you!"
"What were you going to say?" Regulus asked with perfect sincerity.
Lily opened her mouth, then gave up. "Regulus Black, you are far too cunning."
Regulus watched the red hair spilling through her fingers, his mouth curving. "I was genuinely concerned about the power outage."
"I know you were genuinely concerned!" Lily lifted her head, her cheeks flushed. "That's exactly why I can't stay properly angry at you..."
She caught herself mid-sentence, turned her face away, reached for her book, found it already closed, and pulled her hand back with a trace of embarrassment.
She turned back, wrestling her expression into something serious. "Fine. You're forgiven."
Regulus inclined his head with polite gratitude. "Thank you, Miss Evans."
Lily shot him an exasperated look, though the corners of her eyes were still creased with a smile.
Then she leaned forward, sweeping a glance around the Library to make sure no one was watching, and lowered her voice. "What were you actually doing over the holiday? Marcia says you got in a fight with someone and burned down their house."
Before he could answer, she pressed on, concern threading through her tone. "Are you all right? You weren't hurt?"
"Not hurt. Don't worry." Regulus's eyes carried a quiet amusement. "Family business."
Lily watched him, waited a beat, realized he had no intention of elaborating, and huffed. She settled back in her chair, muttering under her breath. "I wasn't worried."
Her fingers wound around the ends of her hair, her gaze drifting from his face to the copy of Basic Alchemy Theory: From Hermes to Paracelsus on the table.
She stared at the gilt lettering on the cover for a moment and noticed the spelling of Hermes was identical to the sullen boy in Slytherin.
Her mouth quirked. She didn't push on the fight.
Family business. Burning down a house. On Regulus, those words somehow tracked.
And if it was family business, then obviously the other side had started it. Her mind arrived at that conclusion with no effort at all, and she smiled again.
"What are you smiling about?" Regulus asked, a little lost.
"Nothing." She reopened her book, picked up her quill, spun it between her fingers, studied the page for a moment, then looked up. "You're really not hurt?"
Regulus met her gaze, the corner of his mouth lifting. "Really."
Lily nodded and set the quill down beside the inkwell.
She seemed on the verge of saying something more. Her lips moved, then pressed together.
Then she settled her elbows on the table again, chin in her palm, her gaze lingering on Regulus's face before she drew it back to her own book.
Regulus opened the book.
Chapter One: the life of Hermes Trismegistus, legendary founder of Alchemy, the Emerald Tablet, Hermeticism.
Chapter Two: foundational theory on the transformation of matter.
Everything in the book could be found in publicly available literature. Metal purification, changes in material properties during potion brewing, the overlap between Alchemy and Potions.
Nothing about the conversion between magical energy and mass. Exactly as he'd expected.
Lily read quietly across from him.
The Library held only the sound of turning pages. In the distance, Madam Pince wheeled a cart past.
A long while passed before Regulus looked up.
The apology just now, forgetting to write. Forgot. The word snagged on something else in his mind. Forgot to write... what else had he forgotten?
It came back to him.
Last term he'd attempted to merge spatial elements into his Patronus construct. The Room of Requirement, the Astronomy Tower. Every attempt had failed.
Hogwarts's spaces had a will of their own. They refused to answer his Patronus intent, demanding some form of recognition or invitation he hadn't earned.
His conclusion at the time: try somewhere else. An ordinary natural space outside Hogwarts should work, at least in theory.
Then the holidays came, he'd gone home, buried himself in the Whomping Willow and Disintegration Curse research, and the whole thing slipped clean out of his head.
His brow creased. His gaze lost focus, resting on the open Alchemy text without reading a word.
Lily sensed the shift and glanced up, catching the expression just as it crossed his face.
She had no idea what he was thinking. She assumed he still felt guilty about the letter, and that dissolved the last stubborn knot of resentment in her chest.
She closed her book, leaned forward against the table's edge, propped her elbows on the surface, and settled her chin on her laced fingers. "All right, all right," she said softly. "I forgive you."
Her voice was gentle, almost coaxing. "Really."
Regulus surfaced from his thoughts. He read her expression, realized she'd misread him, and saw no reason to correct it.
His shoulders eased. "The magnanimous Miss Evans."
"Don't you forget it." Lily gave a prim little huff, lifted her chin from her fingers, and twirled her quill once between them.
The Library settled back into quiet.
They each returned to their books, glancing up now and then to trade a line or two.
By the time closing hour approached, the sky beyond the windows had gone fully dark.
Lily fished something small from her pouch, set it on the table, and slid it across to Regulus.
"Christmas present." She pulled her hands back, fingers lacing together on her knees, her gaze fixed on the object rather than on him. "Took me the whole holiday. Unraveled it a few times."
A small charm woven from copper-red cord, the knots compact, about a finger-joint in length.
The braiding wasn't quite expert. A few knots had come out too large, and the edges showed where she'd undone the work and started over.
The colors were deliberate: dark green and silver-grey. Slytherin's palette.
At the center, the cord formed a star. Its five points weren't perfectly even; one arm stretched slightly longer than the rest.
Regulus lifted it into his palm and traced his thumb across the star's surface.
"Regulus," he said quietly. "The brightest star in Leo."
He turned the charm over. The threads on the back were laid in neat, careful rows. "The heart of the lion. In Latin, it means little king."
Lily's eyes lit up, her mouth curving with barely concealed delight. "You knew?"
Regulus nodded, his gaze warm. "I knew."
"A person named after a star should have one." She tilted her head, her voice bright with satisfaction.
Regulus tucked the charm into the inner pocket of his robes, against his chest. "Thank you, Lily. This took real care."
Lily watched him put it away, her smile widening. "Happy Christmas, Regulus."
She stood, swinging her pouch onto her shoulder.
The corridor torches had burned halfway down, the light dimmer than when they'd arrived.
Lily took two steps, then looked back. "Coming tomorrow?"
Regulus nodded. "Coming."
Her face broke into a smile. "Goodnight, Regulus."
He smiled back. "Goodnight, Lily."
Her red hair swayed once across her shoulders, and then she was heading toward Gryffindor Tower, her steps light and buoyant.
Regulus turned the other way, toward the dungeons.