The Granary is a mobile agricultural processing complex that stands roughly fourteen stories tall. Its central body resembles an enormous grain elevator mounted on six articulated legs, each one thick as a highway overpass pylon. Across its hull, corroded hoppers and intake vents cycle endlessly, pulling soil, vegetation, and anything else organic into grinding mechanisms that have operated without pause for decades. The sound it makes — a low, rhythmic threshing — can be heard twenty kilometers away on still nights.

No one knows what The Granary does with what it harvests. The processed material disappears into internal chambers that no salvage team has ever successfully accessed. Drone surveys suggest the interior contains refinement systems of a complexity that exceeds anything currently manufactured. Some theorize it produces fuel for other Behemoths. Others believe it is stockpiling biomass for a purpose that hasn't yet revealed itself. The machine shows no interest in human settlements unless they happen to be in its path.

The Granary's route follows the old agricultural belts of Iowa, tracing patterns that roughly correspond to pre-collapse farming districts. It has been observed pausing over the ruins of grain storage facilities, extending massive boring appendages into the earth as if searching for something buried. Whatever it finds — or doesn't find — it eventually moves on, leaving furrows in the landscape deep enough to reroute streams.