Thalia is a world. It is a planet that was part of the WorldWeb during the Web Era. It was targeted by the second wave of massive attacks upon the Hegemony of Man that brought about The Fall. During the interplanetary chaos that preceded the Fall, Thalia was hit by terrorist attacks from Glennon-Height royalists after they had been quiet for around 75 years. No further information is provided in the four books regarding this planet.