Robert Muir

Sir Robert Muir was the Chief Constable of Oxfordshire and a friend of the Cranleigh family.

Biography
At Cranleigh Hall on 11 June 1925, Sir Robert spoke of "the Master", who was also called "the Doctor". Sir Robert compared the Fifth Doctor to him after a cricket game.

This reference momentarily confused the Doctor, as he believed that Sir Robert was referring to his Time Lord enemy of the same name. However, it turned out Sir Robert was speaking of the cricketer W.G. Grace. (TV: Black Orchid)

Behind the Scenes
Robin Bailey, Geoffrey Bayldon, John Carson, William Lucas, Nigel Stock and Peter Vaughan were considered for the role before Moray Watson was cast.