Turlough was a different breed of companion for the Doctor. A civil war on his home planet, Trion, resulted in the death of his mother. As his father had been on the losing side, he was exiled from Trion along with Turlough's younger brother, Malkon. Turlough himself was sent to Earth for his crimes. He was attending a public school on Earth when the Black Guardian approached him. Turlough would be given passage away from the Earth, the Guardian offered, in exchange for killing a man known as the Doctor. Desperate to get away from his dull planetary prison, Turlough accepted, and the Black Guardian helped him to infiltrate the Doctor's ship.
During the following two adventures, Turlough continually failed at his task. The Doctor was not suspicious of him, but Tegan of course was, and the Black Guardian was becoming more and more angry with him. At last, Turlough decided he could not go through with it, and he managed to defeat the Guardian.
Turlough is a fairly sullen and acerbic fellow, not prone to forming close personal ties or to emotional buoyancy. However, after his betrayal of the Doctor, he seems keen to prove himself. Tegan's trust in him slowly grows, and soon he is an integral member of the team. Turlough often attempts to persuade people to help him by using charm, although sometimes he finds that commands or simple politeness work just as well. He is a perceptive and shrewd fellow, but can be quite rash. Turlough is also a very strong swimmer, likes to sketch, and knows how to drive, although not terribly well. He tends to take a lot of risks, sometimes just for the fun of it. Unfortunately, Turlough sometimes suffers from the "extra character" syndrome - instead of contributing meaningfully to the plot, he is tied up and kept out of the way for significant portions of time.
The adjectives "conniving", "cunning" and "sneaky" all apply to Turlough equally well. If ever his deceptions or mistakes are caught out, Turlough's first impulse is to blame someone else for what happened. He is a rather greedy fellow, and can be cruel to people who don't actually deserve such treatment. He is quick to give up people for dead. Turlough is also irrationally paranoid, and frequently checks to be sure they are not being followed even when he has no reason to be suspicious. On top of all this, Turlough is a bit of a coward. But fortunately for both Turlough and the TARDIS crew, he is able to move past most of his bad qualities, becoming rather brave and even a bit kind-hearted. The fact that the Doctor had faith in him has made Turlough extremely loyal to the Time Lord. By the time he parts company with the Doctor, he has matured into an upright and responsible young man.
Physically, Turlough has bright red hair, piercing blue eyes, and unusually bushy eyebrows. He usually wears his public school uniform, complete with tie, although eventually he tires of it. On his left arm is a brand of two interlocked triangles, the Mesos Triangle, used to mark Trion political exiles. His title is junior ensign commander, identification code VTEC9/12/44. Turlough met his brother Malkon again when the Doctor took him to the volcanic planet Sarn, where his father's ship had crashed years before. There he learned that all the political prisoners of Trion were no longer persecuted. Although he didn't want to leave, having learned a lot from the Doctor, Turlough reluctantly parted company with him in order to go back home.
