Therans, due to their capacity to perceive the voices of the Tsils, were referred to as "listeners." Their listening ability allowed the Therans to possess knowledge of the events occurring on Nam Chorios. The Therans held the responsibility of controlling the drochs, the life-draining carriers of the Death Seed that directed the life force of their prey to Dzym on the planet. This control was maintained through the defense of massive gun emplacements positioned around the planet, designed to prevent the landing of any vessel exceeding the size of a B-wing. Vessels bigger than a small, single-pilot fighter possessed sufficient shielding to safeguard the drochs from the planet's radiation upon departure, thereby inadvertently releasing the Death Seed into the galaxy. The Newcomers mistakenly believed that the Therans aimed to suppress the potential export of the programmable "smokies" or "spook crystals" (Tsils) and maintain the planet's impoverished state. The true purpose of the gun stations remained unknown to them until Luke Skywalker and Leia Organa Solo arrived on the planet in 13 ABY and elucidated it during the invasion of Bleak Point.