Vertex Citadel

Vertex citadels are citadel‑like complexes at the twelve vertices of the icosahedral rubble shield surrounding the starship Daban Urnud. From these high vantage points, they overlook the adjoining facets and mount equipment that interacts with the wider cosmos.

Appearance and construction

Each vertex is an assemblage of domes, cylinders, gridwork, antennae, and extravagant bouquets of silver parabolic horns. Five massive “knuckles” where shock pistons meet form the base of a vertex; superstructure rises above to house instruments and access ways between exterior and interior spaces. Some vertices are pressurized modules; others include through‑tunnels or exposed mechanisms.

Roles and functions (observed)

• Observatories: At least one vertex is an optical observatory. Its spherical telescope dome is split into two hemispheres that slide apart to open the instrument to space, and the dome itself functions as a large airlock that can be sealed and re‑pressurized for maintenance. Telescopes there are operated remotely over the visitors’ network, while the largest instrument has been described as actively surveying the surrounding cosmos.
• Command and operations: Another vertex is identified in‑story as a military command post, indicating a mixture of scientific and operational roles across different vertices.
• Support for major apparatus: One vertex serves primarily as a support base for the World Burner, with extensive trusswork, plumbing, and lighting; around a hundred suited personnel were seen working on the complex during a period of heightened activity.
• Conference space overlooking major apparatus: At the vertex associated with the World Burner, a pressurized conference room with windows looks out over the assembly, suggesting oversight functions for senior personnel.

Access and relation to the ship

• Vertex citadels sit on the joints where shock pistons converge, tying the rubble shield to the ship’s interior structure.
• Pressurized hatches within a vertex lead inward to corridors and service spaces; from a vertex, travelers can reach the despun Core regions and the rotating Orbstack.

Notable incident: seizure and decompression at a vertex (reported)

• During an assault on the World Burner installation, a detachment of Valers covertly boarded that complex. In the ensuing chaos, Arbran accounts say that two members of the detachment gained leverage at the vertex by placing a shaped charge against the conference‑room window and compelling its occupants to open an airlock.
• Those two then gathered nearby personnel into the conference room, sealed and welded its doors, and locked additional doors deeper into the vertex to isolate it from the rest of Daban Urnud.
• To prevent immediate counter‑entry, they detonated another charge so that most of the vertex vented to space, leaving only a few rooms with atmosphere. They sheltered there after exhausting their suit air.
• Ship responders, focused on reaching the sealed‑in personnel, avoided the vertex for a time, then breached from outside; when the remaining atmosphere escaped, the pair who had held the position died. This episode is reported through Arbran testimony during later medical recovery and debriefing.

Current understanding

Accounts assembled by avout and Sæcular observers depict the vertex citadels as key interface points between the shielded exterior and the inhabited interior of Daban Urnud. Their purposes vary by vertex—observing, commanding, or supporting hardware—and they are staffed or tended by personnel associated with the Geometers. Specific interior arrangements and control practices are reported from close observation and should be treated as in‑world testimony rather than settled fact.