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
Civilised world; home of the Athonian Tunnel Rats
A shadow-shrouded Imperial civilised world whose government is fought over by dozens of rival families, in a gang war waged through the streets and sewers of its hydroponic gardens; it is best known for the Athonian Tunnel Rats it raises for the Imperial Guard. Unknown to its people it was built on the resting place of the Necron pirate king Thaszar the Invincible, and in late M41 his tomb ship tore free from beneath it and levelled the capital, though the rest of the world was left largely unscathed.
Era Indomituspost-Rift
imperium
Civilised world, rebuilding
Still an Imperial world after Thaszar's departure, with hostile wildlife of its own: Athonian fleshflies lay their eggs under the skin of their prey. Chem Dog names it in its Epilogue.
Position
Map frame: 250, 760 in the archive's 0–1000 disk space (core at 500, 500).
Distance from the core: 361 units ≈ 38.4k light years, south-west of the galactic core.
Height above the disk plane: -5.9 units — invented thin-disk jitter, deterministic per record. No published source gives any location a z coordinate.
System: Athonos System
Books set here
1 title in the reading tracker touches this record. Titles link out to the tracker.
Every fact in this record, and where it came from. Editorial derivations say so.
identityhigh
wh40k.lexicanum.com/wiki/Athonos (read directly in a browser on 2026-10-02): 'Athonos is an Imperial Civilised World' (Warhammer 40,000 5th Edition Rulebook pg. 138); rival families, gang warfare in the streets and sewers of the hydroponic gardens, the Athonian Tunnel Rats (pg. 141); Thaszar the Invincible's tomb ship beneath it (Codex: Necrons 8th Edition pg. 29); 'Athonian Fleshflies - Flies which lay their eggs under the skin of their prey', cited to Chem Dog (Novel), Epilogue. NAME-COLLISION CHECK: Lexicanum full-text search for 'Athonos' returns this world, the Athonian Tunnel Rats and Thaszar only; no index record uses the name.
book-joinmedium
MENTIONED for Chem Dog (astra-militarum::am-main::16): Lexicanum Athonos cites the novel's Epilogue for Athonian fleshflies. Whether the Epilogue is set there or only names the world is not stated by any permitted host, so the join is the weakest tier.
TEMPERATE, low. The only look words are 'shadow-shrouded' and 'the hydroponic gardens' its streets and sewers run through (Lexicanum Athonos, citing the 5th Edition Rulebook and Codex: Necrons): a settled, inhabited world rather than a hive, desert or ice ball. The infobox tag 'Civilised World' is a governance category with no palette, and 'former Necron Tomb World' describes what lay beneath it, not its surface, so `dead` was refused; `hive` was refused because nothing calls it a hive world.
gposlow
inferred: segmentum-level. Canon places Athonos in Segmentum Tempestus and publishes no sector, subsector, bearing or neighbour that this dataset can use (Lexicanum Athonos). Placed at [250, 760], inside the stylised 'tempestus' polygon (61 units from its edge, checked) and 74 units from the nearest marker (Kamidar), so it implies no neighbour. The coordinate claims nothing finer than 'somewhere in Segmentum Tempestus'. UPGRADE CANDIDATE: a published sector would replace it. Z -5.9 is the zPolicy value (compute-z.mjs athonos 250 760).
erasmedium
m41: Lexicanum Athonos §Overview, 'This ended in late M41, when Thaszar awoke from his Great Sleep and moved his colossal Tomb Ship from beneath Athonos' surface. The resulting destruction ... levelled Athonos' capital' (Codex: Necrons 8th Edition pg. 29). indomitus: carried because Chem Dog (filed M42) names the world and its fleshflies (Lexicanum Athonos, Epilogue); status 'rebuilding' is our reading of a world whose capital was levelled shortly before, hence the era is low on detail.
no-system-surveyhigh
No systems/athonos.json: a MENTIONED join, and canon enumerates nothing about its system (no star, no siblings; Lexicanum Athonos has an empty System field).
systemIdlow
athonos — editorial: Lexicanum gives no system name, so the record names its own synthesised system, as other unenumerated worlds in this index do.