Tina Drake

 was a 51st century Time Agent who was sent to investigate a temporal anomaly caused by the Fifth and Tenth Doctors. She first travelled back to 1809, where she met the Fifth Doctor in the catacombs of Paris. She was informed by the Doctor that her pseudonym, "Madame Pamplemousse", translated to "grapefruit" and did not refer to a place in the Dordogne. Discovering Cybermen, she escaped via vortex manipulator while the Doctor was frozen in stasis until 1944, as the Cybermen invaded Paris and created an alternate timeline.

Agent Drake couldn't follow the Doctor to the future, so she went back to her home time to do some more investigation before rejoining him and his later incarnation in 1769. She accompanied both the Doctors to find out when the Cybermen first contacted Joseph Delon, and went with them to prevent them from recruiting Delon in 1761. After the invasion was prevented, Agent Drake joked that she would arrest them for meeting past/future versions of themselves, but cordially let them go. (AUDIO: The Gates of Hell)