Arcanum was a city on Amargosa‘s inhabited continent. Situated on the eastern coast, it handled a large percentage of the planet’s food processing. It was destroyed in a fusion blast during the Gelt Incursion.
While a colony ship parked over the city about a week after the invasion, a Marine contingent holed up in the foothills near the ruins. They regularly communicated with the Founders' Mine. The Gelt garrisoned the immediate vicinity while a contingent of Marines under command of Major Hu, formed a resistance in the surrounding hills.
During preparations for the Liberation of Amargosa, the colony transport over the city suffered catastrophic damage from a kinetic device launched from the Challenger, on a mission to notify the resistance that an invasion was imminent. The transport, however, remained usable and floated off the city.
As of 432, a second, smaller Gelt transport, supplied by Hanar, hovered over the city with the original floating out at sea as a supply depot and hospital for those living around the ruins. Rebuilding had yet to begin by this date, and the ruins became a military base under command of now-Colonel Hu. Hu buried three ships gifted to the provisional government by the . One of these he allocated to Suicide and JT Austin on their mission to locate Jayne Best. He informed the pair that, should Amargosa leave the Compact, he would leave with it, regardless of its status or independence after that.