A dense cluster of metal-rich asteroids and shattered proto-planets, the Crucible Belt is one of the Union's primary sources of raw material. Entire lineages work as microgravity miners and ore-refiners here, passing down traditions and equipment the way others might pass down heirloom furniture.

Habitat-hulls cling to asteroids like barnacles, linked by cables and transit pods. Families might not set foot in a standard gravity well for generations.

Life in the Crucible produces a particular kind of Forgeborn: lean, wiry, with a near-instinctive sense of trajectory and momentum. Many of the Union's best riggers and hull-walkers come from the Belt.