Disclaimer: I am not the awesome Marissa Meyer and am making no profit off this work.

! PLEASE READ. This fic contains canon-compliant descriptions of a deadly plague. As such, characters WILL die. If this could be in any way triggering to you given the current covid19 pandemic, please read another fic.

Text in bold = comms, text underlined = directly from Cinder by Marissa Meyer.

Stay safe.

Laure

The vial in Dr Erland's fist glinted up at her. It was barely the size of the pinkie finger on her cyborg hand, but all her hopes were pressed into it. So much hope in such a tiny glass tube. The antidote to letumosis, or so Queen Levana had claimed. A cure to the blue fever. A cure for Peony, her sister. Cinder's thoughts were racing as the door to the office clicked shut behind Kai and she was only vaguely aware that the doctor was talking to her. She looked up at him and saw that his mouth was moving, and his eyebrows were furrowed in a baleful glare. She thought that he might be chastising her for coming to the palace and putting herself in danger from the queen.

She didn't care.

The doctor still seemed to be talking, but Cinder was finding it impossible to register his words above the frantic skittering of her pulse whose speed (as her retina display unnecessarily informed her) had suddenly spiked. Her thoughts were directed in one direction only. Get to the New Beijing plague quarantine. Give the antidote to Peony before it is too late. Get to the quarantine. Now.

"I'm sorry," she gabbled, interrupting the doctor mid-flow. It was quicker not to argue. "I won't come to the palace again while the queen is here, but I had to take the prince's android back to him. I know, I know," she said as Dr Erland's mouth thinned disapprovingly, "but Kai – err, His-Majesty-the-Emperor-to-be, told me it was a matter of national security."

"You have to go. Now." Dr Erland snapped. "What if she decided to come see the lab facilities? What if she saw you?"

Cinder sucked in a quick breath, deciding not to mention that the queen had in fact seen her when she was calming the protestors demonstrating against her outside the palace, given that Cinder had been the only one who Levana's bioelectrical manipulation had not managed to dupe into mindless adoration. That could lead to long and messy explanations that she had no time for. Peony's life was on the line. She had entered the third stage of the blue fever yesterday morning. Her time was running out, and fast. "Queen Levana didn't see me," she lied, "and she won't. I promise to stay away from here until she's returned to Luna."

"Very well," the doctor said, although he still looked far from happy. He gestured at the door. "Now run. Get out of here as quickly as you can, Ms Linh and do not come back until the Queen and her minions have departed."

Cinder stayed rooted to the spot. Her gaze flicked back to the vial. "The antidote-" her voice caught, suddenly weighed down with guilt for what she was about to ask, despite her desperation to save her sister. "I know it's the only sample but – do you – do you need all of it? It was enough for an adult male – allegedly. Could you – Doctor Erland, could you duplicate it with a slightly smaller volume?"

The doctor looked confused for a moment, before his brow cleared. "Ah yes. Your sister." He hesitated for a moment and then nodded. "A promise is a promise. I meant what I said when I told you that she would be the first in line after Emperor Rikan – may his spirit rest in peace – to receive a chance at a cure." He reached for a beaker on his desk. "How old is she?"

"Fourteen."

He poured a quarter of the vial into the beaker before corking it and handing it back to her. "The answer, Ms Linh, is yes. I can certainly try to duplicate it with a smaller volume. I believe this should be sufficient to enable both of us to achieve our ends."

Cinder curled her hand around the supposed antidote, cradling it as though it were made of the most precious crystal. She couldn't quite believe this was happening. "Do not return to the palace until the queen has left," the doctor repeated, and Cinder nodded feverishly, barely comprehending his words. "Thank you," she breathed.

She was already pulling up a comm on her retina display to summon a hover as she pivoted and ran out of the med-clinic. Her feet flew beneath her on the richly decorated carpets and each breath was burning in her chest, with fear and panic, as much as from the physical exertion. Each thump of her footsteps through the maze of corridors became a prayer. Let her not be too late. Let Peony still be alive. And please, by all the stars above, let the antidote not be a cruel trick of Levana.

The area outside the palace was filled with the hubbub of angry voices and protestors once again brandishing their anti-Lunar and anti-Levana signs, but Cinder barely noticed as she hurtled into the waiting hover, the vial still clutched in her right palm. The hover ride to the New Beijing quarantine crawled by as Cinder stared at the city unrolling in front of her, silently willing the hover to go faster. As a metallic voice informed her that she would reach her destination in five minutes, green text spooled across her vision.

Comm received from New Beijing District 29, Letumosis Quarantine. Linh Peony entered fourth stage of letumosis at 17:24 on 18 Aug 126 T.E.

Cinder's heart squeezed. The fourth and final stage of the disease could pass in a matter of minutes. Peony's life was slipping away with each second of this hover journey. She balled her left hand into a fist to stop it trembling, not daring to make any movement which might disturb the antidote in her right and gnawed on her lower lip. By the time the hover pulled up outside the quarantine, she could taste blood.

Cinder took a moment to scan the warehouse area for med-droids which might attempt to stop her entering the quarantine, slipping along the shadows until she was metres away from the doors. Then, she took a deep breath and dashed inside, fear and adrenalin making her stomach roil and bile rise into her mouth. The smell of decay clogged in her throat and the whimpers and rattling breaths of the dying swept through her ears in a confused, miserable rush.

Peony was lying in the same bed, the sheets soaked with sweat. Her skin was covered in blue, red and purple blotchy bruises, the raised flesh giving off a putrid stench. Her fingers, Cinder noted with a sickening clench of her stomach, were tinted blue at the tips. The final symptom of the blue fever before death. Peony was still alive – but barely. Her eyelids flickered open as Cinder approached but she made no other movement to show that she had acknowledged or even recognised her stepsister.

'Peony,' Cinder pleaded, kneeling down next to the bed. 'Peony, it's me. Can you hear me?'

Peony's eyes were glassy and uncomprehending. Cinder snapped her fingers in front of them, in sheer desperation. 'Peony!' she hissed, panic removing any sympathetic encouragement from her tone. 'Peony, concentrate! It's Cinder!' No response. Cinder cursed and, knowing this was probably a terrible idea, gave Peony's shoulders a slight shake. Peony's chestnut hair flopped lifelessly to one side.

'Go…way,' Peony slurred and the words, despite their content sent hope racing through Cinder. She could still talk, if barely. She was not past the point of understanding.

'It's Cinder!' she hissed again. 'I've come to help you.'

This time, her words seemed to have some effect. 'Cin-der?' Peony rasped, her eyes un-focussing, and then re-focussing.

'Peony, you need to drink this.' Cinder shoved the vial under Peony's nose. 'Can you swallow?'

Peony took a rattling breath, but her head bobbed up and down ever so slightly. Cinder coaxed her head off the pillows and carefully parted her lips. Her hands were slick with sweat, and it took her several goes to unscrew the vial, but she finally managed it. She didn't even know if this would work, but she had to try, and Peony was clearly almost too weak to take it on her own.

'You have to drink this, Peony,' she whispered. 'Ok? It's an antidote. A cure. But you have to work with me. You have to swallow it.'

Peony's eyes unfocussed again and Cinder cursed. Every second lost was a moment of wasted comprehension. Every second elapsing made her sister's co-operation less likely. Cinder froze for a moment, torn by the indecision of what to do. Then she took a bracing breath and tilted Peony's head gently towards her. She carefully tipped the clear liquid through Peony's parted lips, before pressing her nostrils closed and clamping a hand over her mouth, desperately hoping that her little sister was not about to suffocate or spit out the precious antidote. Peony grimaced and shuddered, her skin clammy under Cinder's hand, but finally she swallowed once, convulsively. Cinder released her hold on Peony's nose instantly and worried at her lips until she could once more taste the iron tang of blood. Now what?

Peony whimpered, mumbling a confused babble, from which only the word 'sleep' could be distinguished. Cinder squeezed Peony's hand, stilling her own trembling fingers. 'You'll be ok, Peony,' she promised, even though she knew it might well be a lie. 'You're going to live.'

Peony's lips twitched weakly and she closed her eyes, her grip on Cinder's hands weakening and her pulse barely a flutter. Cinder felt a stab of anguish. She had never felt pain quite like this before – a physical, wrenching grief that threatened to break open her chest and split her heart in two, leaving nothing but a withered organ, still sparking with cybernetics. It wasn't enough. She hadn't been enough. She had failed. She hadn't got to the quarantine fast enough. Peony was still dying. The pain of the tears she could never shed throbbed through her temples in a splitting headache, but Peony's eyelashes were still fluttering, however dimly. She couldn't leave her. She wouldn't leave her. Not until the very end.

A minute passed. Then another, and Peony's heartbeat, although painfully slow did not recede any further. Cinder squeezed her eyes shut. Please, please, all of you stupid stars above, let her live. Let Peony live.

She stayed, squeezing Peony's hand, listening to her shallow breathing, and the groans of the dying surrounding them. It felt like hours passed, but her interior clock helpfully informed her that only ten minutes had elapsed. Eleven minutes. Twelve. Twelve minutes, thirty seconds. Thirty-one. Thirty-two.

Cinder realised that she was muttering aloud. Peony's fingers twitched in her palm, slick with sweat. Another comm pinged across her vision and Cinder flinched. This one was from Adri. Mouth dry, she opened it, and the knots in her stomach squeezed themselves even tighter. The hover payment of ten univs had not gone unnoticed by her guardian. The first question of the terse message asked why she considered herself entitled to waste the household income to go gallivanting around the city. The second demanded to know why she had been to New Beijing palace. The prickling feeling crept down Cinder's spine a couple of seconds before her brain realised what the questions must mean. She took a steadying breath, allowing the knowledge to sink in. Adri was tracking her ID.

She had barely managed to squash down the writhing feeling in her stomach when a second comm opened underneath the first. This one had left passive aggressive far behind it.

Comm received from Cinder's No.1 Not a Fan: Cinder you have SIXTY SECONDS TO INFORM ME WHY YOU ARE IN THE CITY OUTSKIRTS BEFORE I REPORT YOU AS A RUNAWAY CYBORG IN VIOLATION OF THE CYBORG PROTECTION ACT.

Cinder flinched and sent back the first excuse she could think of. There's an old parts store. Needed some pre-used machinery.

Is that so? Adri's comm snapped back. Name the store.

Cinder hesitated a second too long in searching up the name of a nearby stall. More green text flashed across her eyes. Don't strain yourself, trying to find a plausible lie. Return home immediately.

Don't you think that I might be in the middle of something? Cinder retorted.

Return home before I am forced to report you, was Adri's only response.

Cinder cursed quietly. She squeezed Peony's fingers a final time and stepped back from the bed. She knew that being caught in the plague quarantines was not an option. "I'll be back," she whispered to her sister, although she didn't know if she would be able to keep her promise. Peony let out a low murmur as she turned on her heel and headed towards the doors at the other end of the clinic.

With yet another twist to her stomach, she recognised the baker's little boy, Chang Sunto, lying in a nearby bed as she was once again forced to stop by a med-droid. His pillow was dark with sweat and his hair was matted to one side. Unable to look away from the child, Cinder presented her elbow for the blood sample proving her clear of letumosis pathogens. "Ashes, ashes, we all fall down." The nursery rhyme from the marketplace slipped out of his chapped lips as his eyes stared at her without recognition. Cinder allowed herself one crushing moment of pity and sadness for him before she ran. She made it approximately eight blocks before magnets hummed above her head. There was a hover waiting for her. A law-enforcement hover.

"Greetings, Linh Cinder," a white android said, wheeling out of the hover and brandishing a taser at her. "Your guardian commands that you return with us."

"What? But – I was already returning!"

"If you come peacefully into custody, this infraction will not be uploaded onto your permanent record," the android continued, unphased.

"I was already coming peacefully!" Cinder snapped.

"– our orders are to apprehend you, by force if necessary, as a citizen in violation of the Cyborg Protection Act," the android finished. It wiggled its taser in a threatening manner. "Do you consent to be accompanied back to the Phoenix Tower apartments, New Beijing, Linh-mei?"

Cinder sneered. There was nothing else for it. "I consent."

The hover was more efficient than the public ones provided for civilians but the fifteen minutes it took to transport her back into the city centre crawled by as Cinder's internal ranting reached fever pitch. She was seething as the android dropped her off in front of the apartment door.

"How dare you send for me like some common criminal?" Cinder yelled, slamming the door behind her.

"Like some common cyborg, you mean?" Adri replied coolly. She was sitting in an armchair and her lack of visible anger inflamed Cinder's still further. "Unfortunately, that is all you are, as you well know. I was perfectly within my rights to act as I did. Indeed, many would argue that I was performing my duty to society. A runaway cyborg must be prevented at all costs. All that data in your head must give you ample reason as to why – what happens when they can't be tracked. Robbery. Murder. Rioting. Destruction."

"I was returning home, as you told me to!" Cinder shouted. "Just as you told me to, despite the fact that I had to leave off what I was doing simply because it was convenient to a whim of yours! Why did you decide that it was so necessary to have me taken into custody when I was already doing exactly what you asked?"

Adri shrugged, standing up and beginning to pace around the room. "You were returning home? Perhaps you were. Perhaps not. It does not signify much. You need to learn, Cinder. Your kind is dangerous to normal people. Just because you do not like it that I can summon you back to where you are supposed to be does not mean that you have the right to gallivant around the city at your whim and all the while my daughter is dying!" Her eyes were bright with tears and her voice quavered on the words. "It could have been you! It should have been you!"

Cinder's heart squeezed. Not with sadness – she had already known how Adri felt. After all, she had been the one to 'volunteer' Cinder to become a guinea pig for the New Beijing scientists trying to find a cure to the blue fever. She still had no idea whether the antidote had worked, even partially. It was possible that Adri was right – that her sister was still dying. The only straw she could clutch at was that she had received no comm of Peony's death. Not yet.

Adri squeezed her eyes shut, shuddering with a mixture of grief and anger. When she opened them again, she made a dismissive gesture with her hand, trying to return her voice to its normal cadence. "Oh, and remind me – where did you get the money for the hover, Cinder?"

Cinder hesitated. "I-" was all she managed before the air rushed out of her. She gasped as she felt herself forcibly shoved backwards onto the chair her stepmother had just vacated.

"Spare me your lies," Adri snapped. Her gaze flicked down to Cinder's boots, lingering on the left one, as if she could see right inside it, through the leathen and vernis to the second-hand cyborg foot which Cinder had bought only days ago. "And take off your shoes."

Sitting on her bed, Cinder inspected her ankle cavity. Her fingers were trembling. In an impressive show of strength, Adri herself had wrenched off Cinder's left foot with nothing more sophisticated than pliers, "as she was perfectly entitled to do in her capacity as guardian," she had reminded Cinder. Her stomach churned as she remembered the feel of Adri's hands yanking on the last remaining connector fibres until the foot finally snapped off. Now there was nothing but a handful of frayed wires at the end of her metal leg. Cinder squeezed her eyes shut until she could see stars, trying to tamp down the anger still boiling inside her. If she screamed and raged and vented her fury on the apartment as she longed to, Adri would be well within her rights to call another police hover and this time, she was fairly sure that such an infraction would be recorded on her permanent record.

"I'm sorry, Cinder." Cinder looked up as Iko wheeled into the room, her blue sensor glowing dimmer than usual. "Adri tapped into my memory banks. I couldn't stop her finding out about the foot. She threatened to disable me." The sensor flickered in what might have been a shudder. "I thought she would."

"What about the car?" Cinder asked sharply. "Our escape plan?"

Iko shook her head. "Only because she didn't think to look. If she'd wanted to, she could have found it." Her metallic voice took on a whine, a clear tell that she was upset. "I feel so useless, Cinder!"

Cinder had opened her mouth to comfort her when a blood-curdling scream sounded from the bathroom. Cinder grimaced, dialling down her exterior volume control until the world was blissfully muted. Her guardian could sort out any spiders herself. She turned her attention back to Iko, but Iko's lights were flashing in alarm. "What?" Cinder asked, turning the sound up notch by tentative notch. Her stomach clenched. Adri was still screaming. Only now, the screams were changing, becoming deeper and they suddenly sounded horribly like sobbing.

Cinder limped across the apartment, using the walls to support herself. When she reached the bathroom, Adri's distress became immediately clear. Her guardian was practically holding herself up by the sink, wracked with sobs and scrubbing at the bruised rash beginning to creep across her right hand. The hand that had removed Cinder's foot ten minutes ago. Letumosis. It had to be. Somehow, Cinder had carried it back from the plague quarantines with her. Bile rose in her mouth. She hated Adri, but she had never, never wanted this.

Adri didn't even glance at her as Cinder collapsed onto the ground. She had given up washing her hands and was staring at her own reflection, her eyes wild, her breaths coming so fast Cinder doubted she would be able to call for help even if she wanted to. She was shaking as she called up a comm to summon the plague droids; her second one that week.

She was still shaking as the droids left, carrying Adri between them. She didn't know how long Adri had been screaming that this was Cinder's fault, that everything was Cinder's fault. She did know that the screams were burned into her internal hard drive.

She was still shaking when a comm flashed across her vision. Cinder flinched so hard she whacked her head against the wall. She opened it, feeling her heartrate double with a sudden, additional spike of adrenalin. Comm received from New Beijing District 29, Letumosis Quarantine: Linh Peony displaying signs of recovery from letumosis a week after entry to quarantine. Discharge in near future hopeful.

The cocktail of emotions which had been swirling inside Cinder for the last hour spiked. She barely made it to the toilet bowl in time. Black dots were dancing before her vision and she thought dimly that she might be hyperventilating. Peony was alive. She and Pearl were about to be parentless. Peony was recovering from the disease. Cinder had transmitted it to her mother too. Peony would be safe. Peony would be destroyed.

WARNING. WARNING. HEART RATE INCREASING. BLOOD PRESSURE INCREASING. HORMONE LEVELS UNSTABLE.

Her sister was going to live. Her stepmother was going to die.

"Cinder?" Iko was repeating her name. "Cinder?" She wondered when Iko had begun speaking. "Cinder, can you hear me? Cinder!"

WARNING. WARNING. RECOMMEND A TEMPORARY SHUTDOWN. REBOOTING IN 3-2-

Terror and relief and guilt and shame and fear and guilt and happiness and guilt and –

Fire exploded down her spine, racing along her nerves and wires, slithering down the metal braces in her limbs. Cinder gasped and the room came into sharp, dizzying focus. Her cyborg parts were scorching hot. Her blood felt like it was singing in her veins. Her left hand seemed to be glowing. Electricity was dancing in her veins. She should be dying. She felt like she was dying. She felt like she was flying, up into a sky where the possibilities were endless – where anything she imagined could happen. She felt like a queen. No, Cinder realized, shaking her head, feeling it clear. She felt – Lunar.

This is my first fanfic so any constructive criticism is greatly appreciated. This could be continued, but I'm happy to leave it as a oneshot for now. Thanks for taking the time to read!