This archive tracks four layers. A record present in 2 of them (M41, IND) is silent in the rest, and says so.
The Horus HeresyM30–M31
[RECORD LOST]
No record for this location in The Horus Heresy.
Age of the ImperiumM32–M40
[RECORD LOST]
No record for this location in Age of the Imperium.
The 41st Millenniumpre-Rift
imperium
Sentinel world; hive world
A hundred and sixty-seven billion people across hive sprawls and forges, separated by dust bowls and guarded reservoirs. Strategically unremarkable, right up until the sky broke.
Era Indomituspost-Rift
contestedImperium Nihilus
Nachmund Gauntlet; permanent war zone
The Nachmund passage — one of the few dependable ways through the Great Rift — opens here, so everything fights for it: Black Legion, orks, genestealer cults, aeldari and the Imperium at once.
Position
Map frame: 330, 268 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 288 units ≈ 30.6k light years, north-west of the galactic core.
Height above the disk plane: 3.5 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
System: Vigilus System
Books set here
1 title in the reading tracker touches this record. Titles link out to the tracker.
derived: Segmentum Obscurus, north-east of Cadia and short of Cypra Mundi, and astride the Great Rift — the Nachmund Gauntlet is a crossing, so the marker sits on the rift line, just on the Nihilus side
wh40k.lexicanum.com/wiki/Dark_Imperium_(Novel named in a tracked book: Dark Imperium (dark-imperium::di-main::1). ) §Differences between editions records that the SECOND edition adds a passage in which Guilliman recalls Calgar from too long away, referencing his service in the War of Beasts on Vigilus. Page-cited on that page. A reference inside the book, not a place the book goes — the link is filed at role 'mentioned'