The Under-Earthmen are a people that dwell deep below Third Earth. These intelligent creatures were feared for the knowledge contained within their many books, which they guard fiercely despite years of confinement below ground having robbed them of the ability to read them.
Due to their negative experiences of life above ground on Third Earth, the Under-Earth People are instinctively hostile and mistrustful, yet they are not evil and will do the right thing when forced to take action.