The Fathomsound is the most unusual of Sepheris Secundus’s mines. Within its enormous basin is an underground lake upon which float thousands of rafts, barges and lashed-together wooden structures that form the home of Fathomsound’s serfs. The frequent blizzards that rip across Sepheris Secundus churn up the waters of the Fathomsound, and many serfs are lost to the freezing waters with every storm. The Flotsam, as this floating city is known, is one of the most poverty-stricken and desperate places on Sepheris Secundus, with its inhabitants literally clinging to life, permanently ill thanks to the fouled water, and condemned to lives spent in the deadly underwater mines.

The barons of the Fathomsound are obliged by planetary law to live within the mine whose serfs they own, but none would willingly dwell on the dangerous Flotsam. Instead, they live in mansions suspended from the edge of the mine pit, hanging from mighty chains and served by precarious elevators and cable cars. The barons typically enjoy taking caffeine on the balconies along the lower surface of these extraordinary homes, from where the Fathomsound is a spectacular sight and its poverty and dangers are not obvious. The mansions swing alarmingly when the wind is up and it is not unknown for them to break free and plunge into the lake. Inside, the furniture and ornamentation is bolted down and visitors to the Fathomsound’s barons have to find their sea legs quickly.