Midnight in Ravencross came with a peculiar silence. Not the peaceful quiet of slumber, but the brittle hush of a city holding its breath. Mara sat at her desk, the rusted coin heavy between her fingers as she watched Lily's chest rise and fall. Each breath seemed shallower than the last.
The indigo aura had spread, seeping into the air around her sister's bed like ink in water. Within its depths, something writhed—a darkness that had no place in a living body. Mara had spent the hours since returning from the Black Market Square pondering about the rusty coin and the Rat King's warning. The only respite she could grasp in between the two was a measly dinner of cabbage soup and molded cheese.
A coughing fit seized Lily, this one so violent it snapped her frail body forward. Blood speckled the sheets, darker than it should be.
"I'm sorry, Master," she whispered, before reading off the cryptic verses from the forsaken book.
Mara's fingers closed around the coin and tossed it.
The coin whirled, glinting in the candlelight. Once. Twice. Thrice—far more rotations than her eyes could trace. It hovered in the air, captivating the anxious healer.
Plink!
It hit her desk, spinning a bit before it lay flat.
A deep sigh escaped from the healer.
Mara's throat tightened. Had she misunderstood?
The winds rasped on the windows, seeping through the cracks and bits of the shattered windowpane.
The candle guttered. In its wavering light, Mara saw her own shadow rip away from her feet and climb to the dripping ceiling. But when it reached the ceiling, it didn't stop. It expanded, stretching and reshaping itself into something that merely wore the mockery of a pale chagrin.
"How disappointing," said a voice like rustling leaves. "I expected more ceremony for my summoning."
The entity that emerged wore Mara's face—or rather, the face she might have had if time spared her family. If life had been only kinder. Its eyes held the same sharp green as hers, but behind them swirled the colors of every disease she'd ever witnessed. Its healer's robes were immaculate, unmarred by the crimson stains of daily practice.
"What on earth are you!" Mara gasped, covering her mouth as she reeled back.
"How rude. First a mundane summon, then such an insolent question."
The figure wiped off the wisps of smoke as it gained a concrete form, tamer than Mara's own composure.
"Pesterio, if you prefer something more personal."
A smile stretched on its face. "Though names have so little meaning compared to intentions, don't you agree?"
The demon's form rippled again, and in an instant it was beside Lily's bed, looking down at her sister with an expression of clinical interest. "Fascinating. My own work, though I don't recall crafting this particular strain. It's evolved beautifully."
"Stay away from her." Mara stepped between them, seething.
"Dear girl, I'm inside her already."
Pesterio traced a finger through the indigo aura, causing it to swirl faster.
"Just as I'm inside every coughing bastard in this delightful city. The question is, what do you intend to do about it?"
Mara paused; her eyes shook with despair. The demon glanced over the healer's shoulder, peering at the desk.
"Ah yes, the Infernal Grimoire. One of many I've scattered through the years, waiting for someone worthy to find them."
The demon's form shifted again, and it wore the bald, clean-shaven face of Mara's master, Grove Hedgeworth. The kind eyes, however, had been replaced by a pair of dark holes that stared into the healer's, and the wrinkles were deeper in the skin laced with scars.
"Your old master found one too, you know. Such a brilliant man. His healing techniques were revolutionary."
"Master would never—"
"Deal with demons? You're right, of course. He chose to let his brother die instead. Such nobility."
Pesterio's form rippled back to Mara's silhouette.
"But you're different, aren't you? I can see it in the way you treat your patients. You understand that good intentions are worthless unless they can bear fruit."
Another coughing fit wracked Lily's body. This time, Mara saw something crawl beneath her sister's skin—dark threads pulsing through her veins. She gnashed her teeth, and her fists clenched to her sides.
"Now, don't ruin that pretty face. I believe you have a favor to ask."
Mara sighed, then pointed at her sister. "Heal her."
"Watch the tone, human," the demonic voice deepened. "Let's try that again."
Reluctant pride etched her face.
"Heal Lily… please. I'll do anything in return." she begged, her brows furrowed and eyes shut tight.
The demon's wicked grin widened.
"Simple enough. I'll grant you the power to heal any disease, no matter how grave. A mere touch will be enough to cure the afflicted."
"And in return?"
"Balance must be maintained. When you heal someone, their affliction must be transferred to another within twenty-four hours. If you fail to choose a recipient, the illness returns to the original victim twice as strong."
Pesterio gestured at the indigo aura around Lily. "Though in this case, I doubt she'd survive even the original strain for much longer."
Mara's mind raced. "I choose who receives the transferred illness."
"Of course, of course. I find human choice far more interesting than gambling. Though I should mention—" The demon held up a finger. "—you'll need to keep precise records."
Smoke condensed in the demon's hand, and a black leather-bound book plopped into its grasp.
"A ledger, if you will, documenting each healing and transfer. The magic requires proper bookkeeping."
"Why?"
"Let's call it professional curiosity."
Pesterio moved to Mara's desk, long fingers trailing across her medical journals. "I so enjoy watching how a healer would justify her choices. Will you transfer the afflictions to the elderly, who have lived full lives? To criminals who deserve punishment? To the wealthy who can afford better care? The possibilities are endless."
A weak voice came from the bed. "Mara?"
Lily's eyes were shut, glazed with fever. The dark threads beneath her skin were spreading visibly now, mapping ridges of corruption across her face.
"I'm here," Mara said, rushing to her sister's side. "Everything's going to be fine."
"Touching," said Pesterio. "But she has perhaps an hour or three left. Less, if the fever wind returns. We have a deal then, I suppose?"
Mara looked at her sister's face, then at the demon wearing her mirrored self.
"How do I know you'll keep your word?"
"I'm not human." The demon's form flickered like a candle flame. "A demon never betrays their words. And this strain I've placed in your sister? One of my finest creations. It would be a shame to let its story end here."
Another spasm shook Lily's body. Blood trickled from her nose, black as ink.
"Yes," Mara said. "I accept your terms."
Pesterio's smile split its face like a gaping wound. It reached out with both hands—one to Mara's forehead, one to her heart. "Then let's begin."
Pain exploded through Mara's body. She felt her bones twist, her blood boiling, her lungs filling with air as hot as raging steam. Through it all, colors blazed behind her eyes—not just the familiar auras of illness, but distorted shades that had no place in the world she knew.
As it ended, she found herself on her knees. The demon stood over her, holding the book.
"Your ledger," it said. "Do try to keep it organized. Now, shall we test your new gift?"
Mara pushed herself up, her body still aching. She approached Lily's bed, watching the indigo aura pulse and writhe. When she placed her hand on her sister's burning forehead, she felt something new—a connection, as if she could reach into the very essence of the disease itself.
The indigo light surged up her arm. Lily's body arched, and for a moment both sisters glowed with the same terrible radiance. Then it was done. The aura vanished, and Lily's breathing eased into the peaceful rhythm of natural sleep.
"Beautiful," Pesterio whispered. "But remember—twenty-four hours to transfer it, or it returns twice as potent. Choose wisely." The demon's form began to fade. "Oh, and one more thing. Don't bother trying to transfer an illness to yourself. The magic won't allow it. That would be far too simple, wouldn't it?"
The demon's figure faded until it became one with the air, leaving only a lingering scent of herbs and corruption.
Mara clutched the ledger, feeling the darkness churning inside her, waiting to be passed on. Already her mind was racing through possibilities. The wealthy merchants who hoarded medicine? The guards who took bribes to let people break quarantine? The criminals in the Under-Warren?
Through her window, she could see the purple-tinged mist rolling through the streets. Somewhere in that fog was her first target. She just had to choose fast.
"I'm sorry," she whispered, though she wasn't sure if she was apologizing to Lily, to her master, or to herself.
She opened the ledger. The yellowed pages were blank, waiting for her first entry. Waiting for her to begin recording how she would balance the healing and the murders to come.
The first fresh page seemed to glow in the candlelight as Mara picked up her pen. She had twenty-four hours to damn someone with her sister's plague. Twenty-four hours to justify her first step down a path she'd despise.