The familiar scent of woodsmoke and old parchment usually offered a fragile comfort, a veneer over the gnawing quiet of Grimmauld Place. Tonight, it felt like an accusation, clinging to the heavy velvet drapes, seeping into the worn rug beneath Y/n’s bare feet. She traced a finger along the spines of the leather-bound books in the drawing-room, her reflection a murky ghost in the polished surfaces. This room, with its dust-motes dancing in the slivers of moonlight, was a sentinel of secrets. Her gaze snagged on the framed, faded photograph of Walburga Black, her scowl as potent in print as it had been in life. Y/n harbored a particular, irrational disdain for Walburga’s taste in curtain tassels. Too ornate, too fussy, like a suffocated scream.
A floorboard creaked upstairs. Not the usual sighing of an old house settling, but a distinct, measured tread. It was too late for Mrs. Weasley to be bustling about, and Hermione, bless her methodical heart, was almost aggressively silent in her movements. That left… him. Katsuki.
Her heart, traitorous and insistent, gave a familiar lurch. She tightened her grip on the book spine, the sharp edge digging into her palm. He was supposed to be at a Ministry conference, some new decree on Muggle-born rights that had everyone’s knickers in a twist. He’d kissed her forehead just this morning, a rough, possessive gesture that still left a phantom heat on her skin. He’d promised to be back by dawn, maybe a little later. Not now. Not the middle of the night.
Ignoring the prickle of unease that had begun to spread like cold ink through her veins, Y/n moved towards the fireplace. The unlit grates seemed to gape, a hungry maw. Her initiative was born purely of habit, the unconscious urge to leave things as she found them. She reached for the small, silver snuff-box on the mantelpiece, intending to make sure the last embers from earlier were truly out. She always did this. A small, obsessive ritual to prevent any lingering sparks from becoming an inferno. It was a silly, illogical fear, this ancient house catching fire around her, but it persisted.
Her fingers brushed against something cool and metallic, tucked almost entirely out of sight within the shadow of the mantelpiece’s ornate carving. It wasn’t the snuff-box. It was a locket. A slender, silver chain, not dissimilar to her own, but with a heavy, polished onyx pendant. It certainly wasn’t hers, nor did it belong to Mrs. Weasley, who favored intricate, golden filigree. Hermione wouldn't wear anything so… ostentatious. No, this was a man's locket. And Katsuki, notoriously unburdened by sentiment or superfluous adornment, never wore jewellery.
The floorboard groaned again, closer now, at the top of the main staircase. She didn’t move. Her breath hitched. The weight of the locket in her hand felt impossibly heavy, colder than it should. It radiated a subtle, almost imperceptible warmth against her skin, almost as if it had been worn recently. Or was it her own body heat transferring to the metal? Her mind, usually quick to rationalize, felt like a clogged drain.
The footsteps descended, slowly, deliberately. Each soft thud on the ancient wood was a hammer blow against her tightly strung nerves. She clenched her free hand, nails digging into her palm. She didn’t dare speak, didn't dare breathe too loudly. What if he wasn't alone? What if this was… someone else? The thought, raw and unwelcome, twisted in her gut. Grimmauld Place was supposed to be secure, yes, but Harry's protection charms had failed before.
A silhouette appeared in the archway, framed by the faint moonlight from the street. It was him. Katsuki. His usually unruly blond hair was slightly dishevelled, his jaw tight. He wore his usual dark travelling cloak, but beneath it, his shirt was pulled slightly askew, revealing a sliver of skin at his collarbone. He looked… strained. And he was holding something. A small, leather-bound volume, unremarkable in its appearance, but clutched with an almost desperate intensity.
His eyes, sharp and crimson even in the dim light, immediately fixed on her. On the locket in her hand. The air in the room thickened, became a palpable pressure. His expression, usually a volatile storm of annoyance or grudging affection, was unreadable. It was a blankness that was far more terrifying than any anger.
"Y/n," he said, his voice a low growl, strained. "What are you doing down here?"
The question hung between them, laced with something she couldn't quite name. It wasn't simple surprise. It wasn't concern. It was a careful, measured edge, like the sharpening of a blade.
She felt a flicker of defiance, old and familiar. "I could ask you the same, Katsuki. I thought you were at the Ministry." Her voice, surprisingly steady, betrayed none of the frantic drumming in her chest. She held the locket up, letting the dim light catch the dark gleam of the onyx. "Did you forget this?"
His eyes narrowed further, the muscle in his jaw twitching. He didn't answer. He simply watched her, the heavy silence stretching, suffocating. The book he held seemed to absorb the light, a dark, heavy mass against his palm. He looked tired, yes, but there was something else there too, something carefully veiled. A guardedness that spoke volumes of unspoken things.
Every instinct screamed at her to demand an explanation, to confront him, but something held her back. The pure, unadulterated shock had frozen her, leaving her suspended in this moment of tense quiet. The locket pulsed against her palm, a faint, unsettling warmth. It felt wrong. Everything felt profoundly, sickeningly wrong. What had he done? And why did the presence of this single, unremarkable locket feel like the unraveling of everything?