Alluka doesn't know how it feels to be whole, the way others are, with just a single soul in a threadbare skin. In each joint, along every curving slide of bone she feels darkness whisper, a loose gas that spills between the gaps in her blood like ink.

Nanika has always been there, softly poking between her atoms, rolling through all the little holes in her body. When Alluka stares down at her skin, she can see Nanika moving, the way she carefully coils under pores and threads her way around hair roots. It is not strange to her, but she has the feeling no one will understand if she tries to explain. The only time she's tried, to the one person who stayed still long enough to listen, his eyes went big and wet and he worried that she was going blind.

'Stupid brother!' she had raged. 'Nanika would never hurt me!'

She didn't know how to explain that it was like the blackness in a room after a light was switched off, or the shadow falling over a well-loved face; a harmless concealment that wouldn't wound.

'Skin thin,' Nanika mumbles, by explanation, one day, the unsteady enunciation of a toddler tripping through Alluka's brain. 'Many holes. Cover up those places. Too easy to hurt.'

'Then heal,' Alluka tells her, no, whispers, because Nanika scares easy and sometimes retreats into a faint buzz at the back of her skull. 'Make it better instead. Like the prince makes the princess better in all the stories.'

'Prince?' Nanika sounds interested, the same brightness blooming in her voice whenever brother is near.

'Yes. You know...when he kisses her? Hee.' Alluka hides her giggle behind her hand the way she remembers her mother doing. It had been a bright, perfect, afternoon after watching two bounty-hunter smack their lips together. Mike had eaten them soon after, of course.

'Heal. Fix. Aye.'

Nanika tests the words and Alluka finds herself stumbling towards a small thing in the garden, a quivering weasel left for dead. Her hand reaches out and there is a flare of white, powerful as the sun beneath her fingers. Alluka can see it, feel it, black extending out and stroking the weasal's muscles, sewing together bone and joint and draining away pools of slathered blood over the grass. She falls asleep soon afterwards, Nanika tucked back into the corner of her mind like a coiled mouse.

She'll have to show brother.

Alluka is shut off from life with only stories, from books and from brother's excited tongue, to illustrate the world outside. This does not make her stupid.

She knows Nanika has killed people. In some way that makes her more of a Zoldyck than Alluka can ever hope to be. For Alluka is unlike her brothers; her muscles are thin and hidden away behind the long sleeves she asks for, tucked away behind skirts that hang down like curtains in a thin, pitiful shield against what will one day happen. Alluka fears it, the day her shoulders will sharpen and lengthen out like armour, the way her throat will bob out like almost every throat in her family does, the only exceptions being her mother and grandmother.

But she won't wish. She won't twist Nanika the way others have tried.

Because Nanika cries when she kills people, when she has to force some of her black out and squash people down, twirling them round and squeezing as though she is embarking on the final step in some strange new recipe. Alluka can feel her when she closes her eyes, a curve in a spine that isn't there, black hunched over with no real body.

'Why hurt?' Nanika asks. 'Why fix? Why ask?

Alluka frowns. 'Why wish, do you mean? Why do they do it when you have to hurt somebody afterwards?'

There is a quiet, almost ponderous moment of silence. And then, very, very sadly, comes an, 'aye.'

Alluka puts down the brush she has been using to work through the fluffy tangle in a toy lion's mane.

'Because they're already hurt,' she decides. 'Or they think they are. And they think they need something to make it better. They ask you to fix it but they always ask for the wrong thing.' And then she smiles softly. 'And you always give it to them.'

'Aye. Love me. I want...' Nanika trails off. It is the first time Alluka can remember it happening.

Love isn't a transaction, she thinks. It is bright and warm and touches me when I see brother.

It would be nice though, to believe that it can work the way Nanika wants it too. To believe that one day, they won't have to be locked in this room. That mother will reach out to touch them both, if only the once. And that Kalluto will not hate them for stealing brother's heart, even though they never try to earn it. And, and-

Alluka swallows down a lump. Chokes it down. Brother has always been enough.

'I love Alluka,' Nanika mummers, mummers with all the weight of a promise, 'I love Killua.'

And Nanika too. One day, she will believe it and smile. And one day, perhaps, the door in front of her will open.