Nigel Stock (21 September 1919-23 June 1986) played Prof. Hayter in DW: Time-Flight. One of his claims to fame is that he is the only actor other than Patrick McGoohan to play Number Six in an episode of The Prisoner. Among his roles was Dr. Watson in the BBC's 1960s series Sherlock Holmes. In Series 2, he played alongside Peter Cushing in the role of Sherlock Holmes.