The underground settlement of the Aenar, a blind and telepathic Andorian subspecies, concealed far below the ice of Andoria's Northern Wastes and protected by a dampening field.
The Aenar compound is seen in The Aenar. Its few thousand inhabitants are pacifists who keep apart from the rest of Andoria, and most Andorians had thought them a myth until about fifty years earlier.
Archer and Shran travel into the Northern Wastes to find them after learning that the Romulan drone ship attacking shipping across the region is being flown by an Aenar pilot. Shran is badly hurt in a fall on the ice, and the Aenar bring both men inside. Their speaker, Lissan, refuses to become involved in violence.
A young woman, Jhamel, defies that decision. Her brother Gareb was abducted from the compound a year before, and she leaves with Archer to use Enterprise's telepresence unit and reach his mind.