A veteran star of the British small screen, Ian Fairbairn made various appearances in Doctor Who over the years. His first role was as Questa, a human who lived in a colony secretly ruled by Macra, in 1967's aptly titled The Macra Terror which was followed by guest stint as International Electromatics researcher Mark Gregory in The Invasion (1968), in which he faced off with the Cybermen. In 1970 he played technician Bromley alongside the Third Doctor in Inferno and his fourth and final appearance followed suit in The Seeds of Doom (1976) in which he played Doctor Chester. He passed away on 5th December.