They are divided into castes . The Selenites live in a large complex under the surface of the moon from which they rarely venture , with the exception of the ' exiles ' . The Selenites " banish [ these ] dregs of their society , the criminals and psychotics , " to the surface of the moon . There are three Selenite exiles with whom the player can interact ; they live on the surface and sleep in their isolated underground stables at night . Each exile have two different plants on either shoulder with which they share a special bond .