Thrayne

 was a scientist at a research base in Devon, researching superconductivity. He was determined to summon something supernatural he called his old self. He showed the Third Doctor, Alistair Gordon Lethbridge-Stewart and Sarah Jane Smith round the facility and demonstrated one of the experiments. He had some alien material which concerned the Doctor. He hunted the Brigadier. The Doctor discovered that he had lived in the area since 1855 as he was from Cyntheros. He had been exiled on Earth. He was hunting the Icewalker and this is why he built the research base after he was foiled in 1855. (AUDIO: The Devil's Hoofprints)