Ambulon is a bizarre sight indeed, claimed by many to be a
hive in its own right. The entire city is mounted on the back of
a machine that slowly walks across the unstable rocky regions
in the centre of Scintilla’s main continent. The machine is
extremely old, and was almost certainly already on Scintilla
when the Imperium conquered the Calixis Sector. It is probably
a pre-Imperial artefact, constructed by a civilisation that fell
before the foundation of the Imperium, though some claim it is
a relic of pre-Heresy terraforming technologies. Certainly the
skeletal ruins of moving constructs similar to Ambulon dot the
central steppes. Ambulon’s unusual form affects every aspect of
life in the city, from the industries that employ its middle-class
citizens to the city’s customs and folklore.

Control of Ambulon
Ambulon is navigated via a huge and very complicated control
centre, powered by arcane engines of incredibly occult design,
in the area corresponding to its head. The Guild Peripatetica,
highly superstitious engineers who keep the secrets of how
to control the citadel-mechanicus, are constantly scrambling
about the intricate controls making tiny adjustments to keep the
edifice moving. Many tales of hive folklore dwell on the terrible
consequences should Ambulon ever stop, varying from the city
simply collapsing, to the machines becoming self-aware and
devouring the humans clinging to its back. The noble houses
quarrel constantly over what orders to give to the guild, but they
are also well aware that they should not bully or otherwise cross
the Guild Peripatetica lest the engineers point them towards a
crevasse or other dangerous obstacle and hold the citadel to
ransom. The path that the machine takes is crucial to harvesting
the deposits of oil, natural gas and precious stones that form
Ambulon’s contribution to Scintilla’s tithe, and everyone has
an opinion about where it should go next. Ambulon stalks
the wastelands, mining and harvesting the planet’s natural
resources, supplying the manufactories of Hive Sibellus and the
foundries of Gunmetal City. Neither could function without
Ambulon’s resources. Ambulon tours the steppe wastes once
every twenty-eight months, slowing to minute speeds in order
to dock with Sibellus and Gunmetal City for a few days to
offload ore and mineral resources. Between these celebrated
ceremonial times of docking, Ambulon supplies Sibellus and
Gunmetal City by way of regular land trains: ore-cargo crawler
pods many kilometres long.

Life on Ambulon
Ambulon’s constant movement means that even the most
solid buildings are in danger of being shaken off the city’s
structure. This in turn means that the city’s wealthiest and
most important districts are located in the places where they
are least likely to be destroyed, especially along the citymachine’s
Spine. The Spine’s buildings are rarely as big as
on hive spires, since space is at such a premium on Ambulon’s
carapace, nor are they as tall, as they have to endure the
constant swaying of the city-machine’s slow, rolling gait.
The style of the Spine sees elegance and even minimalism preferred to the grotesquely grandiose ornamentation
common in the great hives. The nobles of Hive Sibellus,
in particular, consider Ambulon to be a cultural backwater,
whose nobles neglect the proper pursuits of beautifying
their city and venerating their dead.
Ambulon’s equivalent of the middle hivers are the hundreds
of thousands of workers who inhabit tenement blocks piled
up on the vast, shield-shaped back of the city-machine. These
tenements are plagued by cityquakes caused by the city’s
movement, and are all shored up and extensively repaired after
past collapses. Few streets run between Ambulon’s buildings
since there is not enough space for them, so the middle classes
tramp to work across the roofs of the tenements, or even
through each others’ homes. Almost all the middle classers
are engaged in harvesting or refining the raw materials that
Ambulon gathers from the igneous wastes. The “head” of the
city is equipped with immense drills that can be lowered into
the rock, and when the city strikes oil, thousands of flexible
pipelines are lowered from the edge of the city to pipe up
as much of the oil as possible as the city-machine passes by.
Working on these pipelines, which are controlled by webs
of chains like the strings of vast puppets, is very dangerous
and requires a hardy breed of men and women with no fear
of heights. Ambulon’s many refineries process this oil into
promethium fuel, some of which is piped back into the citymachine,
while most forms the majority of the city’s tithe
contribution, to be delivered to Hive Sibellus and Gunmetal
City. Other citizens sift through the rock thrown up by the
drilling to pick out precious stones, which are then worked
into industrial components, or cut for jewellery in workshops
inhabited by generations of gemcutters (considered a
hereditary occupation on Ambulon). Ambulon’s lack of space
means that every citizen must justify his presence there and
unemployment is illegal. Each household in the middle city
is tied to a particular refinery, workshop or other industry,
and its members may not work anywhere else. It is vitally
important for every middle citizen to be properly recorded in the Rolls of Justification which each place of industry
maintains, because if they cannot prove to the authorities of
the Spine that they are permitted to fulfil the role in which
they work, they are banished to the Underbelly.
Ambulon’s “underhive” clings precariously to the belly of
the city-machine. It is known by a variety of colourful names
such as the Underbelly, the Guts, the Vitals or the Hivegroin.
Clusters of hovels blister down from the city-machine like
warts, connected by makeshift catwalks and rope bridges.
Many thousands of people live only a footstep away from
plummeting to their deaths towards the rocky ground that
constantly grinds by hundreds of metres below. Underbelly
settlements are often scraped off the city-machine’s underside
by ridges or peaks that the city-machine walks over, or are
simply shaken off by the city’s movement. Life is short and
very difficult here, and the Gutscum live off the detritus of
the carapace above, constructing scoops to catch the effluent
and waste thrown off the edge of the city, or they form
bandit gangs to prey on the citizens who work near the
edge of the city-machine’s back. One prominent feature of
the Underbelly is the cages hung from the edge of the city
above containing prisoners condemned to the much-feared
punishment of “dangling”. The prisoners are locked in a
cage attached to a long chain, which is then flung off the
edge of the city-machine and left to dangle, swaying with
the city’s movement, until the prisoner starves and the cage
is hauled back up. Hundreds of dangled prisoners hang from
the city at any one time, and the Gutscum sometimes use
them as target practice or, on very rare occasions, “rescue”
them to induct them into Underbelly gangs, enslave them or
pit them against one another in bloody gladiatorial fights.
Ambulon folklore maintains that some dangled prisoners
have survived for months hanging below the city, thanks
to divine intervention from the Emperor, and were released
when the cage was brought back up again to live saintly
lives. In practical terms, however, dangling is a cruel, drawnout
death sentence.


Rejoice For You Are True Pieanator