Barton was a Vulpanan doctor who lived on the planet Vulpana during the end of the Golden Millennium. She tended to the Seventh Doctor after he was bit by a poacher. Barton could not transform into a wolf-like form, but was still affected by Vulpana's moons. Consequently, when Jaks added an artificial Fifth Moon to the planet's orbit to interfere with its inhabitants' responses to the moons, it caused Barton to lose control of herself and attack the Doctor. (AUDIO: The Moons of Vulpana)