6. Companions: Liz Shaw
Liz Shaw was the Third Doctor's first companion, and she was the only one to never get to travel in the TARDIS, due to the exile. This was a completely new direction, as viewers were used to the Doctor and companion traveling to different places in the TARDIS. This was not to happen with Liz. She was highly intelligent in science and was hired by the Brigadier to work for UNIT. Liz did not last too long, however. She was in the show for Jon's first season, when Caroline John decided to leave. And the departure of Liz was not very well-written compared to others. She left at the end of Inferno, and as a viewer, you don't really know it's her last episode.