Dortmun developed a bomb he hoped would be effective against the Daleks, but it failed. He wanted to set about developing a new bomb, but was forced to go on the run when the Daleks began searching for the rebel hideout. He gave Barbara Wright his notes to give to the First Doctor. He attempted to use his new bomb on a Dalek patrol in London, but was killed in the attempt. (TV: The Dalek Invasion of Earth)