Sabetha

Sabetha was a young woman sent by her father, Arbitan, to find the keys to the Conscience of Marinus. She instead became enslaved in the city of Morphoton. After being freed, she accompanied the First Doctor and his companions in their search for the keys.

She and Altos were romantically involved, a relationship exploited by the Voord Yartek. (DW: The Keys of Marinus)