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
Poisonous fungus-jungle world of the Fenris System, assailed by daemons in 999.M41
Fenris's sister world and one of the three inhabited worlds of the Fenris System: a poisonous greenhouse of sprawling fungus growth under boiling purple clouds, its people living in subterranean cities carved from the root boles of the jungle above a magma sea. At the end of M41 the Space Wolves fight the Daemon Princes of the Infernal Tetrad here (Curse of the Wulfen).
Era Indomituspost-Rift
none
Destroyed in 999.M41
Gone: destroyed at the end of the Siege of the Fenris System, its shards falling on the system's other worlds for years afterwards (Lexicanum Midgardia, after War Zone Fenris: Wrath of Magnus).
Contested record
Segmentum: Lexicanum's Midgardia infobox says Segmentum Solar. It is in the Fenris System, so it follows the Fenris record's segmentum (obscurus) and that record's own dispute note rather than re-arguing it.
Position
Map frame: 338, 398 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 191 units ≈ 20.4k light years, north-west of the galactic core.
Height above the disk plane: -5.8 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
Every fact in this record, and where it came from. Editorial derivations say so.
identityhigh
wh40k.lexicanum.com/wiki/Midgardia (read in a browser with fetch-page.mjs, 2026-10-12): 'Midgardia was a world of the Imperium and sister planet to Fenris'; 'one of three inhabited worlds of the Fenris System, orbiting the Wolf's Eye alongside Frostheim and Fenris'. Infobox System: Fenris System; Class: Destroyed, former Death World. The body already exists in systems/fenris.json (id midgardia, orbit 2, seed 67); this record gives it an index entry. NAME-COLLISION CHECK: no index record uses the id or label.
book-joinhigh
wh40k.lexicanum.com/wiki/List_of_Daemon_Princes VISITED for Curse of the Wulfen: (read 2026-10-12) cites the novel's Chapter 8 for all four Infernal Tetrad princes (Arkh'gar, Mordokh, Malyg'nyl Needletongue, Tzen'char) 'Fought with the Space Wolves on Midgardia', and for Malyg'nyl being 'nearly killed by the axe of Logan Grimnar' there. One chapter, so visited.
segmentummedium
obscurus, following the Fenris record (same system); the Midgardia infobox says Solar, the same dispute the Fenris record already carries.
classmedium
'death' (green jungle), chosen by the look: 'a poisonous greenhouse. Sprawling fungus growths covered its surface under boiling purple clouds', settlements 'carved from the complex root boles of the jungle above' (Lexicanum Midgardia, citing Champions of Fenris). The infobox's 'former Death World' was not the reason. The magma sea is underground and not drawn.
gposhigh
derived: identical in x and y to Fenris's [338, 398], being a world of the same system. Z -5.8 is the zPolicy value (compute-z.mjs midgardia 338 398).
erasmedium
m41 (the novel's end of M41; renders the record class) and indomitus (class dead: Logan Grimnar destroyed the planet with Morkai's Tooth and 'shards of Midgardia fell to the surface of the other planets of the Fenris System', Lexicanum Midgardia, citing War Zone Fenris: Wrath of Magnus). Allegiance m41 'imperium', indomitus 'none'.
survey-bodymedium
systems/fenris.json body 'midgardia' given class 'death' on the same evidence (it had none), keeping its seed 67 so the globe readers have already seen keeps its shape.