The Clansmen were a group of tribes who lived in caves below the gravesites on a Royal Cemetery Planet. The cancer-causing radiation from the caves generally killed them before the age of 22 cycles. Parts of their group, the "Lost People," were members past the age of 22 who began to show the effects of radiation; these "lost people" never "took the stone." When babies were born, the older members (around 22 cycles) "took the stone" which was to jump from a cliff into a sonic net, which could cushion their fall or could let them die from the impact.