Who are the Archbuilders in the novel, Girl in Landscape?

The Archbuilders are the dominant indigenous species on the Planet of the Archbuilders. They are called Archbuilders because they used to build stone structures like arches. However, they ceased building edifices after they managed to alter the planet’s environment to always be temperate. They also created food that grows on its own and does not need to be cultivated.The Archbuilders have extraordinary linguistic capabilities and are fascinated by the limitations of the English language. Most Archbuilders left the planet a long time ago in order to explore other parts of outer space.

A few Archbuilders live near the human settlement. Their names are Hiding Kneel, Truth Renowned, Lonely Dumptruck, and Gelatinous Stand. Nugent accuses settler Hugh Merrow of having sexual relations with Truth Renowned. Nugent later kills Truth Renowned. Nugent falsely accuses Hiding Kneel of sexually molesting Martha Kincaid, and Hiding Kneel is almost killed by the settlers.