Sir Robert Muir was the Chief Constable of Oxfordshire and a friend of the Cranleigh family.
At Cranleigh Hall on 11 June 1925, he spoke of the Master, who was also called the Doctor. Sir Robert compared the Fifth Doctor to him after a cricket game. This momentarily confused the Doctor as he believed that he was referring to his enemy of the same name. However, Sir Robert was speaking of the cricketer W.G. Grace. (TV: Black Orchid)