COMPANION FOLLOW UP: SUSAN FOREMAN

Susan was always looking for an exit.

Susan was the Doctor's grandaughter. She was attending Coal Hill School in Shoredich, London, until two of her teachers followed her home and discovered she was an alien "from another time, another world".

Origin: Gallifreyan (presumably, as Gallifrey is not named until 1973)
Seasons: 1-2
Tenure: 23 November 1963-26 December 1964
Reason for Leaving: Unceremoniously shipped with rebel fighter David Campbell in The Dalek Invasion of Earth.
Assessment: Susan is the companion who kicks off the entire Doctor Who series, unfortunately she'll never be that interesting again and Carole Ann Ford got tired of screaming all the time so she left. Her best serials are Marco Polo for her touching relationship with Ping Cho, and The Sensorites where her nascent telepathic abilities greatly helped with communicating with the aforementioned Sensorites.