Corin Burke rolled a bead of cold tallow between his thumb and middle finger until it flattened into a gray smear. The Great Hall smelled of scorched goose fat and boiled cabbage, but three seats down, Gregory Goyle was sucking on a peppermint humbug. The sharp, medicinal stink of the herb made Corin’s gums ache. He loathed peppermint. It was an offensive, vulgar sweet, favored exclusively by people trying to hide dirty tongues or rotting molars.
Corin wiped the tallow onto the underside of the oak trestle. His skin felt slick. He hated the grease, but pinch-rolling the dregs of burned-down tapers was better than tapping his knuckles against the table, which made the older boys look at him.
Across the salt cellar, Draco Malfoy had not touched his plate.
Draco’s signet ring—the heavy silver one bearing the Malfoy crest, an antique that had belonged to his great-uncle—clicked methodically against the stem of a pewter goblet. Click. Pause. Click. The rhythm was erratic, dictated by the tremor in Draco's right thumb. Draco’s collar was too loose; the starched linen gaped at the nape of his neck, showing two yellowish bruises just above the cervical vertebrae, spaced exactly like thumbprints.
"The wind is turning," Blaise Zabini said from Corin's left. He did not look at Draco. He buttered a roll with surgical precision. "We’ll have frost on the pitch by morning. Slughorn won’t cancel practice for the house team, though. He likes watching people turn blue."
Corin said nothing. He slid his hand into his robe pocket, fingertips finding the cold, jagged teeth of an escapement wheel.
It was brass, no larger than a Galleon, salvaged from the carcass of a sixteenth-century French scrying clock his grandfather had bought off a bankrupt apothecary in Knockturn Alley. Three nights ago, Corin’s trunk at the foot of his four-poster had been opened. Not blown open—the lock was unpicked with a slender bodkin, the sort of delicate work only someone who feared the noise of an *Alohomora* would bother with. The brass wheel had been sitting in Corin’s velvet repair pouch.
Now it was missing its twin. The escapement worked only in tandem; without the second wheel, the retrograde movement locked entirely.
Draco had stolen the wrong piece.
Corin stood up. His knees made a dull pop beneath his heavy winter trousers.
"Leaving?" Blaise asked, eyes still fixed on his butter knife. "The pudding hasn't arrived. Treacle tart, I imagine. It usually is when the weather turns vile."
"I have an essay for Vector," Corin said.
"Vector took your Arithmancy text yesterday," Blaise remarked, voice level, devoid of curiosity. He withheld the rest of the thought, the obvious question of why Corin would lie about a subject he was currently failing. Blaise was skilled at letting silences curdle until other people filled them with their own confessions. Corin refused to give him the satisfaction.
Corin stepped away from the bench and moved toward the entrance hall.
He didn't look back to see if Draco followed, but he knew the Malfoy timing. Draco waited four seconds, just long enough for the Slytherin table to turn its collective attention to the arrival of the dessert platters, before sliding off the bench.
The flagstones in the entrance hall were slick with tracked-in mud from the rain lashing the courtyards. Corin turned left, bypassing the grand staircase that led toward Gryffindor territory, ducking instead into the dim, vaulted corridor that curved behind the portrait of the fat monk drinking cider. The air here was ten degrees colder. It smelled of damp limestone and the sulfurous bite of green wall-torches.
Corin stopped by the arched alcove housing the broken statue of Gregory the Smarmy. He pulled his penknife from his sleeve.
He didn't open the blade to threaten anyone. The habit was automatic: he opened the smallest scraper and began paring the dried ink from beneath his fingernails. The scrape of steel on horn was quiet, rhythmic. It calmed the sour flutter in his stomach.
Footsteps echoed off the ribbed vaulting. Quick, light, uneven.
"Burke."
Draco emerged from the shadows near the tapestry of the drunken warlocks. In the torchlight, his skin had the yellowish hue of curdled milk. Dark circles, purple as crushed sloes, bruised the skin under his pale gray eyes.
"You left your dinner," Corin said. He did not pocket the penknife.
"Don't play the fool," Draco snapped. His voice was cracked, raw around the edges, entirely stripped of the lazy drawl he used in the common room. "You were watching me. You’ve been staring at the back of my skull since Tuesday."
"Because you were in my trunk, Malfoy."
Draco didn't flinch. A year ago, he would have sneered, spat out a threat involving his father, or laughed. Now, his jaw set so hard that the corded tendons in his neck stood out like wires. "I don't know what you're babbling about. If your rubbish went missing, blame the house-elves."
"The elves don't carry hairpin picks made of beaten lead," Corin said evenly. He stepped forward. He was half an inch shorter than Draco, but broader through the shoulders from years of hauling heavy crates of tarnished silver through the cellar trapdoors at Borgin and Burkes. "You took the left-hand drive wheel. From the scrying clock."
Draco's hand twitched toward his pocket. "It's junk. A scrap of brass."
"It's a balance regulator," Corin corrected. "And you took the wrong one. You took the left-hand. It only rotates counter-sunwise. If you force it into a standard spring spindle, the teeth shear clean off. Then whatever you're trying to sync stays dead."
Silence dropped between them, heavy and suffocating. Above them, the castle groaned as the wind struck the western ramparts. Water dripped somewhere in the dark—a slow, hollow tap against the flags.
Draco’s chest rose and fell in shallow, jerky movements. "Who told you I was syncing anything?"
"Nobody," Corin said. "My uncle Caractacus told me before I boarded the Express in September. He said Lucius had an old piece of furniture moved out of Wiltshire two winters ago. Something paired."
Draco took two rapid strides forward, his hand plunging into his robe and whipping his wand out before Corin could raise the penknife. The hawthorn tip pressed hard into the soft hollow just beneath Corin's left earlobe. The wood was cold. Draco was trembling so violently that the wand vibrated against Corin's skin.
"Say another word about my father," Draco whispered. The smell coming off him wasn't expensive cologne anymore; it was cold sweat, old parchment, and the dry, suffocating dust of dried moths. "Go on. Say it. See what happens to you."
Corin kept his chin up, though his heart hammered against his ribs. The pressure of the wand tip hurt, but Draco’s knuckles were white, drained of blood. A boy ready to cast an Unforgivable did not tremble like a wet birch leaf.
"If you curse me, the corridor echoes straight down to the staff room," Corin said, voice low and flat. "Snape is down there. You want him up here?"
Draco’s eyes flashed with sudden, feral hatred. "Snape doesn't know a damn thing."
"He knows you're failing Potions. He knows you haven't turned in an essay since Halloween."
"He doesn't know what I'm doing!" Draco spat, though he didn't lower the wand. His breath came fast, hot against Corin's cheek. "None of them do. They think they can manage me. They think I'm going to run to them when it gets hard."
"I don't care about your family," Corin lied. His thumb worked the ridge of the penknife, the brass casing warm in his palm. "I care about the wheel. If you break the escapement on that thing, whatever passage you're trying to hold open collapses while something is halfway through. Do you know what happens to bone when a spatial hinge snaps shut?"
Draco didn't answer. But his wand drifted a fraction of an inch away from Corin's throat.
"My uncle had a wizard bring in a cabinet from a broken set in sixty-four," Corin said, keeping his voice quiet, measured, like he was calming a skittish kneazle. "The man tried to step through from a cellar in Leeds to a parlor in Whitechapel. The anchor was misaligned by four degrees. He arrived, Malfoy. His front half did. The rest stayed in Yorkshire."
Draco swallowed. The click of his throat was loud in the empty corridor.
"Give me the left-hand wheel," Corin said. "I'll give you the balance pair. Properly matched, with the brass ground down to fit the sleeve. But you owe me two Galleons for the alloy, and you don't touch my trunk again."
"I don't need your help," Draco rasped, but his hand moved inside his pocket.
He didn't pull out the brass wheel. Instead, his fingers emerged empty, clutched into a fist.
"Tomorrow night," Draco said. "The fifth-floor corridor. Behind the statue of Boris the Bewildered. Midnight."
"Ten o'clock," Corin countered. "Filch walks the fifth floor at midnight with the cat."
"Ten," Draco agreed bitterly. Then, before Corin could speak, Draco shoved him back against the damp stones of Gregory the Smarmy's plinth. The edge of the stone dug into Corin’s hip.
Draco turned and walked away, his robes billowing around his thin ankles, disappearing around the bend toward the dungeons. He left behind only the bitter, dry scent of sulfur and old dust.
Corin exhaled. His breath bloomed into pale vapor in the chill corridor.
He reached into his pocket and pulled out the right-hand wheel. He looked down at it.
It wasn't brass.
Under the sickly green flare of the wall-torch, the dull yellow metal wasn't shining the way brass ought to. The patina was wrong. It had a faint, iridescent film clinging to the interior cog, like the oil that sits on the surface of poison. When Corin ran the pad of his thumb across the teeth, the skin didn't catch on clean metal; it felt cold and damp, like rotten lead.
Something was corroding it from the inside out.
"Burke."
Corin snapped his hand back into his pocket, turning on his heel.
Professor Snape stood six paces away at the corner of the corridor. The Potions master moved without the rustle of cloth; he seemed simply to condense out of the shadows. His black eyes were fixed entirely on Corin’s closed hand.
"Curfew is in twenty minutes," Snape said softly. His voice possessed none of the breathless fury Draco carried. It was level, cold, and entirely opaque.
"I was returning from the library, sir," Corin said.
"The library is in the opposite direction." Snape did not raise his wand. He kept both hands concealed within the deep folds of his sleeves. "And yet, you linger by the statue of an idiot, in a corridor known primarily for drafts and damp."
"I lost a quill," Corin said.
Snape took a single, slow step forward. The torchlight caught the greasy sheen of his black hair, throwing deep, hollow shadows across the sallow skin of his cheeks. He looked tired—not the brittle, desperate exhaustion that plagued Draco, but an ancient, bitter fatigue.
"Mr. Malfoy appeared somewhat agitated as he descended the stairs," Snape said, his voice dropping another octave. He did not ask a question. He simply dropped the fact between them like a lead weight.
"I didn't speak to him, Professor."
Snape stared at him. The silence stretched until Corin could hear the blood thumping behind his own eyes. There was an intrusive, oily pressure against Corin's mind—a light, testing brush against his thoughts, familiar to anyone who had spent an hour in Snape’s dungeon. Corin forced his mind to dwell on the sour stink of Goyle’s peppermint humbugs, the greasy feel of the boiled goose, the scraping of his penknife. He clamped down on the image of the brass wheel until his knuckles hurt.
The pressure receded.
"Ten points from Slytherin," Snape murmured, "for wandering. If I find you outside your dormitory after the hour strikes, Burke, I shall ensure your next three weekends are spent disemboweling horned toads for the third-year practicals."
"Yes, sir."
Snape turned to leave, his cape sweeping the dust from the stones. He paused, not looking back.
"Keep your hands in your pockets, boy. The stone here has a way of leeching the warmth from things that ought to stay buried."
With that, he was gone, his black shape dissolving into the gloom toward the stairs.
Corin stood motionless until the soft pad of Snape's boots had entirely faded. Then, slowly, he withdrew his right hand and held it up to the faint light.
The skin on his thumb, where he had touched the greasy film on the cog, had turned gray. A dead, chalky patch, completely numb to the touch, was spreading slowly toward his first knuckle. When he pinched it with his penknife, he felt nothing at all.