Brubble Medicius had the First Doctor, Susan Foreman, Barbara Wright and Ian Chesterton tested for their genetic heritage. He only found Susan to be human as the Doctor fed a false reading into the machine he used. He spent his time vivisecting aliens to find a cure for a plague. He didn't believe Clubwell as he completely believed the propaganda. He learnt he was used as a plague carrier for Mummy Martial. (AUDIO: For the Glory of Urth)