The iridescent sphere of miasmic bile hovered above the bucket rim. Dr. Yvaine Helstrom stood motionless, lips parted, staring at the suspended liquid. Her dropped clipboards lay scattered across the linoleum, pages fanned across the wax. “What in the blazes…?” Yvaine’s voice was a rough whisper, a sound she hadn’t realized she was capable of. Her gaze snapped to Corvin, who met her stare with ancient weariness, fingers splayed as if conducting a miniature orchestra. He looked utterly unconcerned, as if levitating toxic waste was a common afternoon diversion. “The essence of the Hollow Rot,” Corvin stated, his voice a low rasp, completely devoid of explanation or elaboration. He did not bother to clarify that he spoke of its primordial, unmanifested form, not the mundane viral strain circulating through the city. Such nuanced distinctions were, in his experience, wasted on the uninitiated. Yvaine blinked, then shook her head as if dislodging a persistent fly. “The… the flu? This glowing ammonia-mixture is the flu? Morstan, what are you doing? Is that some kind of chemical reaction? You know the rules about unauthorized experiments.” Her voice picked up a frantic edge. Her focus flicked between the floating globule and Corvin’s flat expression. “Do you have any idea how volatile that could be? What is it going to do? I’m going to have to sedate you if you don’t put it down immediately.” Corvin snorted with dry contempt. Sedate him? The Grandmaster of the Obsidian Vials? He had once synthesized a calming draught from the pulverized marrow of a mountain ghoul. The thought was laughable. His attention drifted past her, toward the alcove where two painted walls met. A heat-shimmer ripple wavered in the air. Drawn by Tasia’s lingering scent—a faint trail of rot the hound had tracked since her afternoon visit—the scavenger prowled unseen. A low-tier beast of the lower hells, but lethal to the unfortified. “This is no reaction, child,” Corvin drawled, tightening his grip on the invisible currents. The green sphere quickened its beat, answering his call. “It’s a cleansing. A particularly messy one, for the benefit of your neglected senses.” Without another word, Corvin’s arm lashed out. He snapped his wrist forward, launching the venomous droplet across the ward on a tight, silent trajectory straight toward the alcove. A harsh, wet shriek split the room, shrill as metal grating across bone. Yvaine recoiled, clapping both hands over her ears. The alcove air warped, then seized into solid matter. A canine silhouette resolved against the wall, broader than any timber wolf. Its frame was stitched from roiling shadow and exposed ribs, twin orange embers burning where its eyes should sit as the venom struck its sternum. The hound thrashed as the venom corroded its shadow-flesh into sloughing tar. Boiling black ichor splattered the wax tiles, hissing and carving dark craters into the finish. The beast clawed its own ribs while its forelegs came apart. Corvin stepped in, his hospital slippers whispering over the floor. He brought his heel down in a sharp, snapping arc against the beast's dissolving snout. The impact crunched like dry pine branches. The beast’s orange embers sputtered out. Corvin stomped two more times in flat, methodical cadence, driving the remaining skull fragments into paste. Black-green splatter flecked the baseboard and soaked the hem of his gown. Under his heel, the matter broke into thinning black brine that evaporated in greasy coils, leaving rings of rime and etched burn rings across the linoleum. A faint, metallic tang hung in the air, oddly reminiscent of ozone and decaying copper. Yvaine could only stare, mouth agape, her scientific mind struggling to reconcile what her eyes had just witnessed with every known law of physics and biology. Her fingers twitched toward the dropped clipboards before falling limp. The door to the ward swished open once more, and Dr. Aris Penhaligon strode in, a cheerful, oblivious smile plastered on his face. He carried a small, brightly colored stress ball. “Ah, Corvin! Just in time! I was hoping to catch you before your evening dose of ‘calming elixir’ – otherwise known as chamomile tea. I brought you a new stress ball, a delightful shade of cerulean.” Penhaligon paused, his gaze sweeping over the ward. He glanced at the scattered papers, at Yvaine’s bloodless face, and at Corvin, who stood with one slipper planted beside the charred gouge. Penhaligon’s smile didn’t falter. “My, Corvin, what spirited activity! I see you’ve been engaging in some vigorous shadow-boxing! Excellent for cardio, absolutely excellent! A wonderful breakthrough in kinetic therapy, wouldn’t you agree, Dr. Helstrom?” He clapped his hands together, ignoring the acrid, cold haze. “Such focus! Such energy! Perhaps we can incorporate more of this… *vigorous* self-expression into your daily regimen!” Yvaine found her voice, though her throat felt stripped. “Dr. Penhaligon, there was… an anomaly… Corvin was—” She stopped, looking between the acid-etched tiles and the patient's bored posture. Phantasms and floating muck were clinical grounds for commitment. Corvin flicked two fingers at Penhaligon. “Quiet, charlatan. Your nursery games catch fewer devils than a torn rag.” He turned his piercing gaze back to Yvaine, ignoring the residual black grime on his gown. “You,” he commanded, his voice sharp with ancient authority. “Fetch me three dead rats. Fresh, if possible. If not, the morgue freezer will suffice.” Yvaine stared at him. “Dead… rats? Morstan, what are you talking about? We don’t have dead rats. This is a psychiatric facility, not a biological research lab. And you expect me to just… go get them? After what you just…” Corvin cut her off, his eyes narrowing. “Do you wish your kin to fester and dissolve from the inside out? Do you wish this entire wretched city to rot into grease? Fetch the rats, woman. Or perhaps you prefer to watch the world burn while clinging to your quaint medical dogmas.” He gestured vaguely at the lingering frost on the floor. “The antidote requires certain… components. Primordial components. And a suitable vessel for synthesis.” Yvaine’s epidemiologist instincts, dormant under years of bureaucratic purgatory, suddenly flared to life. She knelt, tuning out Penhaligon’s humming, and dragged a gloved finger along the rim of the burn ring. It was cold, unnaturally so, and the residue was fine, almost like ash. A deep, unsettling curiosity warred with her terror. She carefully scraped a tiny sample into a sterile vial she always carried, a habit from her plague investigation days. Penhaligon, still beaming, patted Corvin’s shoulder. “Wonderful initiative, Corvin! Asking for materials, engaging with your environment! Perhaps you’re thinking of a new art project? A sculpture of some kind? We can certainly look into procuring some… non-living models for you.” Corvin shrugged Penhaligon’s hand off his shoulder, watching Yvaine with cold tolerance. The woman possessed at least minimal survival cunning. An hour later, in the basement pathology station, Yvaine pressed the charred scraping between two glass coverslips. She dialed the objective lens down, breath catching in her throat as the optics brought the specimen into focus. The cellular structure, microscopic and horrifying, perfectly matched the samples she’d collected from the city’s new, incurable ‘flu’ epidemic.

Shadowboxing the Unseen