Aulian Thorolis was a Dascarian. Her ancestors had sold the family land to the First Doctor, a disgraceful act for a Dascarian. The Doctor had bought the land to protect the People of the Trees, a species the Dascarians considered to be primitive savages. Aulian was determined to regain ownership of her family's land, no matter the cost, including the extinction of the People.
She hired Zusala to steal the three statues of the Great Ones, hoping to force the People off the land. She killed Zusala for failing to bring her one of the statues, and when the Fourth Doctor arrived on the planet to help the People, Aulian took Leela hostage in exchange for the statue she did not have. When she tried to kill the Doctor, her weapon fired into a force field holding Leela, and the beam reflected back to her, killing her. (PROSE: People of the Trees)