Sienna Astrid Helvig

History (11) · last changed 08 August 2026, 19:50

Sienna Astrid Helvig Born c. year 326 Other names Nenna Species Homo Sapiens (Lyall-Helvig Chimera) First appearance The Glass House, chapter 1

Sienna Astrid Helvig (born c. 326) is a figure of the C9 universe, the elder of the Helvig twins, and later a diplomat to the Voidomorphians. She is a Lyall-Helvig chimera and an empath. Her records place her origin in a future timeline around year 350, in a post-collapse sector, which is where she and her sister were born and which is not where they grew up.

She is the daughter of Chryssander Randolf Lyall-Helvig and Amaryllis Rigel Helvig, and the twin of Celestine Elsa Helvig. She carried the Helvig name from birth. She was called Nenna as a child.

In the grove

The twins arrived places before anyone remembered inviting them. Celestine came with a piece of fruit and her boots on the wrong feet, and Sienna stopped to switch them without comment^[1].

She brought tea. She made it the way she did most things, with more attention than the task appeared to need, and it came out better than it had any right to^[1]. The tea of rebirth is hers: klak leaves from the same grove, processed a particular way she worked out by accident, which is how she works most things out, by paying attention for longer than anybody asked. There is about a minute between the right temperature and mint water, and inside that minute it makes a body feel slept, whatever the night was^[1].

She ran the paths quietly and efficiently, with the quality of somebody attending to things nobody else can see. She feels what the people around her feel. Not as a skill, the way Marcus puts it, but as weather: it simply arrives, and you get used to it or you do not^[1].

The morning the House opens on, the twins stopped their game in the upper branches and Sienna sat very still on her branch with her eyes open and not looking at anything in the grove^[1]. Later she came down, sat beside Eevi without a word, and said nothing for a long time, and Eevi let her^[1]. Then she brought the tea down in a clay cup and said to drink it first^[1].

In the kitchen she cooks with a specific oil she brought from somewhere and never said where^[2]. The twins set the table every morning without being asked, which is one of the small facts about people that goes unnoticed until the day it stops^[2].

When fifty armed men arrived, the twins were forty metres off, running circles in the grass, entirely unconcerned^[3]. Sienna appeared beside Chryssander without his noticing, which she does, and which he had stopped finding uncanny, and asked the boy his name^[3].

In the tesseract her hand found Celestine's wrist and Celestine's hand was already there^[4].

The facility

The compound suppressed her empathy for weeks. On the ghost operation it was coming back in fragments, the signal finding its frequency again, and she used what she had: eyes closed, building a map of the perimeter out of presence and absence^[5].

Afterwards, when Celestine went quiet, Sienna sat beside her and offered the quiet rather than speaking into it, because her sister does not speak into quiet and has to be given it first^[6].

Physiology

Sienna's epidermis secretes a malleable polymer, a synthetic skin she can shape over her own features or someone else's. It feels like skin and behaves like a seal, and at her best a disguise is a pore-perfect replica that holds for two days. She wears faces to survive a place: as a soldier she is respected, as a Voidomorphian she is not attacked.

The same control turns inward and outward as medicine. At mastery she can knit complex organ damage, at a cost to herself.

Her empathy is not a reading she performs but a channel she has. At its clearest it becomes conversation with things that are not human, which is the ability the rest of her life turns on.

She is built like her mother, coordinated and fluid.

Character

She does not have her sister's twitch. She is patient with information and looks for the reason underneath an action, with a slowness that becomes an asset in negotiation. In a war zone she keeps her hair in a bun and her clothes clean, and the order is not vanity.

Through the early years she is the one who cleans up after Celestine. Later she began making contact with the Voidomorphians without authorisation, having worked out that they were sentient, and spent the rest of her life making people forgive the monsters.

Family

Sienna is the daughter of Chryssander Randolf Lyall-Helvig and Amaryllis Rigel Helvig, and the twin sister of Celestine Elsa Helvig.