Captain Wrack was an Eternal who participated in the race across the Sol system for Enlightenment. She was in league with the Black Guardian and channelled the power he gave her to destroy her competition. For the race, her ship, the Buccaneer, was modelled on a pirate vessel and she sabotaged her opponents' ships from a secluded room in the bottom of her ship. The Fifth Doctor and Turlough threw Wrack and first mate Mansell overboard into space before they reached the Enlighteners. As they were Eternals, they were merely displaced, and didn't truly die. (TV: Enlightenment)
Behind the scenes
"Wrack" is an old word meaning "Destroyer," which reflects Wrack's personality.
