On Caladan with RhomburEdit
She was chosen by Rhombur Vernius to be his concubine when he and Duke Leto Atreides I arrived on Wallach IX for Rhombur to choose a mate. Tessia won Rhombur's heart from their first encounter together.
As Rhombur experienced the grief associated with the loss of the prestige of House Vernius, and their fiefdom on their home planet of Ix, Tessia was a constant source of inspiration and strength to the displaced nobleman. Later, when Rhombur was tragically scarred due to the assassination attempt of his sister Kailea Vernius on Leto, which resulted in the death of his nephew Victor Atreides; Tessia was the first to encourage Rhombur to have the will to live on.
Re-Established on IxEdit
After House Vernius was re-established on Ix, and the subsequent expulsion of the Tleilaxu, the fortunes of Rhombur and Tessia rose accordingly. Later, Tessia was impregnated with the sperm sample from Rhombur's dead half-brother, Tyros Reffa, to secure an heir for Vernius, and the child was named Bronso.
When Rhombur and Tessia attended Leto's wedding to Ilesa Ecaz, that Bronso had copper-colored hair, and the three seemed very happy. During a conversation, when Leto proposed Rhombur to send Paul to Ix to continue his studies, both Rhombur and Tessia told Leto that Ix was not the same place he had visited long time ago, and that the influence of the Earl Vernius (Rhombur himself) on Ixian policy and government was declining due to the power of the Technocrats over the Ixian society.
In 10,188 AG, Jessica and Paul visited Ix so that Paul could spend time as an exchange student in Vernii City, just as his father had done decades earlier. To Jessica's dismay, while there, the Bene Gesserit guilt-caster Stokia and three other Sisters visited Tessia Vernius. They demanded that Tessia produce more children for the Gesserit breeding program, which Tessia refused.
Unbeknownst to Jessica, Stokia used her psychic powers to put Tessia into a comatose trance, which rendered Tessia helpless.
Rhombur was unable to help his poor wife, and Dr. Yueh could do nothing to help her, who began to waste away. The Sisterhood demanded that Tessia be take with them to Wallach IX, where they would nurse her and take care of her. In grief, Rhombur let them to take his wife away.
Many years later, during the rule of Paul Atreides, she remained missing.
Behind the ScenesEdit
It was never established in any of the novels as to whether Tessia had any orders from the Sisterhood to influence Rhombur, or to guide him on any certain path. She was simply presented as someone who constantly had Rhombur's best interests at heart.