Althea Vestrit is the youngest daughter of Ronica and Ephron Vestrit and the younger sister of Keffria Vestrit. She seeks to regain the family liveship Vivacia, which she considers her birthright, from her brother-in-law Kyle Haven.
Althea is stubborn and fiercely independent. She clashed often with her mother and sister during her youth.
After a blood plague killed the three Vestrit sons, Ephron raised Althea as the heir to Vivacia. Althea grew up on Vivacia's decks and developed a bond with the ship.
At her father's death, Althea is shocked to learn that her mother has given Vivacia to Keffria's husband Kyle Haven. Kyle, a Chalcedean who believes women have no place aboard ship, removes Althea from Vivacia and installs his son Wintrow Vestrit, whose schooling as a priest Kyle has interrupted for this purpose.
Kyle soon makes his plans known to make Vivacia a slaver ship, to Althea's and the rest of the family's horror, as a liveship will not tolerate so much human suffering. Keffria and Ronica begin to question their course to install Kyle as captain, despite Kyle's assurances he will treat his slaves gently.
After her family liveship, Vivacia, is stolen by King of the Pirate Isles, Captain Kennit Ludluck, Althea worked aboard the liveship Paragon, with Brashen Trell, whom she later begins a relationship with.
After a battle with Kennit, Althea is lost in the water, and is later recovered by Kennit, who locks Althea in Wintrow's room (formerly Althea's own room), forbidding his crew to see her. He himself visits her regularly, bringing meals laced with a sleeping drug, and later rapes Althea. Following her rape, and believing her true love Brashen to be dead, Althea is on the verge of suicide, but is able to save both herself and her ship from this fate.
Althea finally is released and lives on Paragon with Brashen Trell, whom she later marries. The two have a son, Boy-O, who initially lives wth them aboard Paragon but later leaves to spend some time aboard the Vivacia.