Thanks to his association with the Doctor, Mickey went through a great change, from cowardly idiot to 'defender of the Earth.' However, that's nothing to Turlough. When he joined the Fifth Doctor, he was a would-be assassin! His victim? Why, the Doctor, of course. An alien refugee with no way back to his homeworld, Turlough was living as a schoolboy in an English private school when an old enemy of the Doctor's, the Black Guardian, made him a deal. He would return him to his own planet if he would kill the Doctor. After helping the TARDIS crew, Turlough was invited on board the TARDIS - giving him a perfect chance to fulfil his task. However, he became a better person in the Doctor's company and eventually managed to banish the Black Guardian, proving his loyalty to the Doctor. Even after this, Turlough was always secretive and less ready to lay his life on the line for the Doctor's cause than many of the Time Lord's other friends. For this reason, he remains one of the most different and interesting companions.
