Lucy Martin was the daughter of Richard Martin. When Sebastian Grayle proposed marriage to her in 1806, she declined. It however turned out he wanted to sacrifice her to his masters. After her father was murdered by Grayle, in an alternative timeline, she travelled with the Eighth Doctor to help defeat Grayle's masters, giving Charlotte Pollard the vital message, to use the fast return switch three times, to travel back to Roman England.
After the defeat, the Doctor took her back to her estate, where she arranged her father's funeral, only to see her father walking around, due to the timelines having been corrected. However, a mysterious being arrived, with a taste from the chronon particles that inhabited Lucy, and killed her. (AUDIO: Seasons of Fear)