01:09, Fifthsol 6th M6, 2226

Shiro's coordinates take me to a dilapidated pod complex overlooked by a bioreactor plant. The sweet odour of cellular agriculture wafts from the factory, probably the major employer of the poor souls living in the pods it overshadows.

A woman — judging by her trailing plait, bindi and shirt adorned with peacocks — opens the door warily and sweeps tired eyes over me, ushering me in with murmurs of "Thank the gods."

Just inside the door a little girl lying on a worn divan raises her head in confusion before sinking down again into sleep. The pod is ruinous but tidy, not quite a shade den yet not somewhere I'd expect to see a child. The lady soothes the kid with a rub to the head and a "Shh, darling," before leading me up a tight spiral of stairs.

The rooms on my way up are all shut. Drawings and paintings in a range of childish styles line the walls, some daubed by the hand of a toddler, some pieces of great technical detail. I must be in a foster home. At age four I'd been lucky enough to be taken in by wealthy foster parents who quickly adopted me, though since qualifying as a doctor I've treated countless Eris children whose lives are a colourful patchwork of foster homes.

A delicate sketch of a snow-capped stratovolcano, unmistakably Mount Fuji, is the final exhibition piece displayed on the dim stairway before we come to an attic room devoid of furniture but a small bed.

In the gloom I almost miss him. Shiro is crumpled next to a wall, his chest heaving. My foot throbs in sympathy at the thought of him climbing so many stairs into this ghastly loft on a wrecked ankle. At least it's the last place that wardens or IndoChina would look.

Shiro's hair is slicked with sweat. Vomit stains his shirt. Frightened eyes look up at me, and my heart twists with the most intense grief. I pray to Shiva that this is a particularly bad phase in the crests and troughs of his slow demise by radiation poisoning, and not his final moments.

I crash to my knees beside him, cradling him with one hand and rummaging through my medical bag with the other. Medicine bottles tumble out in my panic, my muscles rigid with fear of him dying in my arms.

Shiro can barely lift his head to look at me. "Can't be sick... Earth..."

"Shh, we'll talk later, OK?" I whisper, tucking his ice-cold body against mine, rubbing at frozen limbs. I ready a syringe while his head lols against my shoulder, chilled fingers grasping for me. "I'm going to give you an analgesic and an anti-emetic then I'll help you to my hov. We'll rest in my pod, then we'll get you on that 'porter, OK?"

The strange woman watches me with interest as I press cautious kisses to Shiro's hair and murmur nothings about mountains and blue skies and thick warm atmospheres. "I'll get you to Earth, I promise."

The woman says, "He didn't tell me about you."

"We're friends." My heart floats with pride as I say it, then plummets at the implication. How can Shiro be so alone? At his weakest moment he called me, of all people. I must be his only friend.

A few moments of stillness, and Shiro's breathing seems to settle. I ease him up onto his knees, the woman rushing to aid us. She prattles on as we navigate each step painfully slowly, Shiro's lead weight between us. "Earth will be so good for you. No radiation, no spacewalks, normal gravity. You'll get better in days."

I have no idea how we manage to descend the stairs without the three of us tumbling down them, but eventually Shiro is safe in my hov.

As I turn to thank the woman I notice something remarkable about her in the light of the floodlit bioreactor factory. The shadows cast on her face highlight something I'm sure that I've seen hundreds of times before, but I can't recall where: wrinkles. When was the last time I'd seen someone over fifty who wasn't underground?

"Respected, can I please ask your age?"

"I'm sixty."

"But you're not underground."

She smiles. "I was one of Isamu Kida's test subjects for the metabolic implant forty years ago."

I can't believe what I'm hearing. She has first generation meatware, the original prototype chip designed by Isamu Kida. Anyone older than her, those of the pre-meatware generations, moved to the other Dwarfs with their extensive underground living to prevent radiation poisoning.

"I was fitted with the metabolic implant when I was twenty, one of a hundred adults who took part in the first trial. The youngest three of us were able to make successful neuromorphic bonds to the implant. The brains of the other ninety-seven subjects rejected it. That's when Kida-san realised that only babies' brains can bond to meatware without rejection."

"Is your meatware still OK after all this time?"

"In forty years I haven't had to report to the hospital once, or go underground. That meatware trial was the best thing to happen to me."

"What happened to the other two adults whose brains bonded successfully to the meatware?"

"They stayed with Kida-san. They probably still work for him, in that beautiful brick building in the middle of the city." She prods me to the hov. "Go. Take care of Shiro."

The hov drives us at a slow pace to my pod. Shiro clings onto me in the shower as if terrified he'll be swept away with the water. I'm relieved to see traces of Mount Fuji visible under angry pink scar tissue from the pulser shot on his chest. If his wounds are healing his meatware can't be moribund, and with Earth's warmth and light and air he'll have many more years before him. He'll get to see the real Fuji-san soon.

In a few hours Shiro will either be safe in the Pinhole to Earth, or he'll have been taken from me by radiation poisoning. He won't be in any state to help me to get Daiyu back from Kida Biotech. I resolve to save Daiyu myself, whatever the cost to me.

I pat Shiro dry and slip an old yellow shirt over his head. He lets me inject him with more anti-emetics and painkillers before he falls asleep nestled against me. I drift quickly into a dreamless sleep.

~~☆☆☆~~

05:00, Fifthsol 6th M6, 2226

My alarm startles us. We greet the sol with yawns and stretches, our bodies still tangled together. 

"Shiro," I manage to get out through my yawn. "Let's go."

He stretches on the bed like a long cat. Rest and care have restored him from the wraith of yesterday to his usual abrasive self. "Your pod is so boring. No pictures, no ornaments."

"I'm either at work, in the metaverse, or asleep. I don't have time to enjoy ornaments." I watch him wrestle open the wrapper of some vend momos he's produced from a pocket. "Let me guess. Your pod has photos of volcanoes everywhere."

"And waterfalls and islands." He nibbles at pastry, looking up at me from time to time. "You're always so smiley."

The comment has me smiling all the harder. "You make me smile."

"Thank you for yesterday."

"I like taking care of you. And I like your friend, the lady."

"Anushka? Yeah, she's the best." He pats down his clothes — my clothes — and slides his lenses on. "I have to go. Finally off this Dwarf."

"Have you got contacts on Earth? Friends?"

Shiro's eyes glaze over: he's busy in his lenses. "My Dad," he murmurs.

"Your Dad is from Earth?" Bewilderment clouds my mind. Shiro isn't an Edger.

If his father is a citizen of Earth, Shiro can't possibly be a descendant of emigrants to the Dwarfs. He can't be one of us Edgers, driven by poverty and criminal amnesty 150 years ago to relinquish citizenship of Earth for the privilege of working ourselves into the dust of Eris. I don't understand why Shiro is even on a Dwarf.

My head begins to hurt trying to fathom it all. "If your Dad lives on Earth, why are you stowing away? Why don't you have a passport? Why can't he just come to Eris and get you? Why all the—?"

"I'm not going to live with my Dad, Heems. He's a bad person. He left me here." Another moment of tinkering in his lenses, and my pod door pops open. Shiro has managed to hack my pod security in under thirty seconds. "I'm going to Earth to blackmail him."

I'm afraid to ask more questions. I'd expected that getting to Earth had been Shiro's end goal, not merely the first step in a long set of horrendous challenges. Blackmailing a father who seems to have exiled him on a Dwarf sounds too heartbreaking to contemplate.

He nudges me out of the pod and chatters during the hov journey about the intricacies of defrauding IndoChina Mining, hacking various Spaceport security systems, bribing Customs personnel, and navigating the spiders' web of organised criminality required to get him into the Pinhole.

By the time we arrive at the Spaceport, Shiro is fizzing with joy. I've only ever experienced the briefest glimpses of his wit, but seeing him so animated makes me understand exactly how I fell in love with him so quickly, so deeply and so completely.

"You're shivering." Shiro takes my hand. "When did you last feed?"

The past hours with Shiro had made me momentarily forget that I'm a parasite, and that I'm starving. I shove my shaking hands under my armpits. "When I drained those IndoChina guards four sols ago."

"You said you need to feed every five sols."

"I've decided to not feed anymore. Ever. Today I need to do one last thing. A favour for a sick friend. Then tomorrow night..."

"No." Shiro grabs me by my shoulders. "You can't just... die."

I smile. "It's OK, Shiro. I'm ready." I root in my pocket and retrieve my data key, holding it out to Shiro. "Take this."

"What is it?"

"Thirty thousand Rupees. For you."

"You're mad!" He tries to press the data key back into my palm, but I squirm away. "I can't take this!"

"Money's no use to me anymore. It never was, really. I need you to be safe on Earth."

"Thank you." He secretes the key into a hidden pocket. "How will you... do it... tomorrow night?"

Tears overwhelm me, and I brush manically at my face. It's not the idea of dying that hurts. It's the fact that I'll never see Shiro again. "I thought... I'll just suck some shade and go to sleep... forever. Like... like we were going to do in the storm."

"Don't go near any shade dens. They're dangerous places." He pulls his shade pen from his trouser pocket and slides it into my palm, closing my fingers over it. 

Shiro wraps me in his arms, then sweeps out of my hov. I watch him limp away, quickly losing sight of his gracile form amongst the cluster of hovs, shuttles and Spaceport domes that make up Eris Customs. I did it. I helped to keep the most precious thing in my life, Shiro, safe.

I leave a message on Jaya's lenses. "He's OK. He left Eris. I'll go to Kida myself. Promise to get Daiyu back."

Jaya replies immediately. "I'm sorry he's gone. Are you OK?"

The magenta text hits me like I've been pulsed in the heart.

Shiro's gone.

That same decades-old grief descends on me like a shroud. I crumple into my hov seat in a paroxysm of tears.

Unsure of how many minutes I've been weeping, a rattle outside my hov makes me jump. 

The hov door pops open. 

Shiro clambers back in, dragging his tortured leg behind him. He settles into the hov seat with a smile. "I was thinking..."

I smear hot tears across my cheeks. "Shiro?"

"My boss... She's not going to like it, but we can ask her to hack your meatware."

I stare at him like he's gone utterly mad. "Get on that 'porter, Shiro. Now."

"If there's a chance—"

"You have half an hour before that 'porter enters the Pinhole." I nudge him towards the hov door.

"Listen. She might help you, for the right price."

No. Shiro needs to get on that fucking 'porter. I breathe the words slowly, "If your boss can't fix me, you'll have lost your only chance to escape Eris. Now get on that 'porter."

"Maybe there'll be another chance to get to Earth."

"Radiation or IndoChina will kill you first. If you don't go now, you'll regret it!"

He clutches at my hands. "I regretted leaving you the moment I got out of the hov."

"Why are you doing this?"

Shiro presses his forehead to mine and laughs, a deep rumble like a rockslide on Eris's sandflats. "I like your smile."

"This isn't funny, Shiro! If it doesn't work you'll have sacrificed yourself for nothing."

"If it doesn't work, and she can't fix you, then tomorrow night we'll make love and get shade-brained and fall asleep together and never wake up. Like we were going to do in the storm." Shiro's face is suddenly close, his voice a hopeful whisper. "Please, Heems. I want you more than I want to go to Earth. Please."

Wrapped in Shiro's embrace, my parasite heart takes flight and soars on mountain thermals. Can his smuggler boss cure me somehow? At what price? For a heady moment I let myself imagine what it would be like to be cured, to touch Jaya and Daiyu and never bring harm to them, to eat a meal with Shiro without it draining me. To share our final moments in blissful sleep, or to start the rest of our lives together.

"OK. Let's try this."

A moment of tinkering in his lenses, and Shiro has control of my hov. The console is suddenly awash with pink, the coordinates of our city centre destination flashing bright: a building in between Eris-1's market and the hospital. A building that takes up a full eighth of the city centre's dome. A building of curved brick and tempered glass.

The Kida Biotechnology building.

My heart skips a beat. "I thought we were going to see your boss."

"We are."

"You work for Kida?"

"I am Kida. Technically my boss is Megumi Kida. She also happens to be my sister."

My jaw hangs, slack and quivering. 

The sister that Shiro lamented when he was about to die in the storm is the best bionics engineer in the Solar System. If anyone can cure me, Megumi Kida can. There's hope for me. Hope for Daiyu. Hope for all of us.

But, as the hov skirts between pod complexes and factories towards the market I gaze at Shiro, and my skin begins to crawl. Shiro's sister has let him live as a battered and bruised thief trailing a mangled ankle. How could the most powerful woman on Eris, the queen of meatware, have allowed her own brother's metabolic implant to die? Why is Shiro reduced to living in rented hovels above shade dens and dive bars, stowing away in a pitiful plan to blackmail his father? Why has Isamu Kida, the pioneer of meatware, returned to Earth and abandoned his children on Eris?

"No, Shiro." I slap at the hov console, desperate to leap out, but the controls have been locked by Shiro's hack. "You can't do this."

"I want to."

The magnitude of Shiro's sacrifice hits me with the force of a pulser wave. There must be a reason why Shiro has chosen lingering death over fulfilling his destiny as an heir of Isamu Kida.

"It's you, isn't it? You're what Megumi Kida wants. You're the price she'll ask for curing me."

"If there's any chance to cure you, I'll take it."

"Not if it means hurting you!"

"Meg won't hurt me, I promise."

I wish I could believe him. Hope for Shiro's safety withers and dies as we reach the shadows and curved glass of the Kida Biotech building.

The iris scanner glows red on Shiro's approach to the glass door. He holds his tired eye to the camera. The scanner switches to green.

I've walked past these red bricks innumerable times. This time I'm finally brave enough to enter. I wonder if Shiro and I will ever come out again.