A renowned scientist, Rubeish was near-blind and had to wear powerful spectacles. When scientists began disappearing, he was confined by UNIT to the research facility for his safety, as were many other scientists. It was here that Rubeish became acquainted with the Third Doctor. He also met Sarah Jane Smith, who was masquerading as her aunt the virologist, Lavinia Smith.
Rubeish was transported to the Middle Ages by a Sontaran named Linx. He was almost hypnotised to work for Linx, but he was saved by his low vision. He found a microscope lens and heated it so he could see more clearly.