Witcher was a car salesman who was on the train that was transported from 1993 Earth to Hogsumm in 2680 by a Fortean Flicker. He believed that they were still on Earth, but that it had been devastated by a nuclear war and that the people on the train were the only survivors. He elected himself leader of the passengers and dismissed the Seventh Doctor's claims that they were on another planet.
Witcher and the other passengers were captured by Postine and taken to Sheldukher, who shot and killed him. (PROSE: The Highest Science)