The Dominatrix was an in-system vessel attached to the Gnostic Ascension and under the nominal command of Quaiche. The vessel's on-board intellect had become familiar enough with Quaiche to anticipate his needs and desires, and even smelled like him, despite the attempts of the Ultras to "decontaminate" it.
In 2615 it was assigned to investigate the 107 Piscium system for anything of value. On the planet Hela it found just that. Unfortunately, due to its limited intelligence, the ship performed a maneuver while Quaiche was not on board without taking into account that his lover, Morwenna, was; this resulted in her death due to extreme g-forces.
In 2727 it was revealed that Quaiche had built his cathedral, the Lady Morwenna, around the Dominatrix. He attempted to use it to escape his doomed former home, only to have it malfunction and fail to save him.