Factual error: As Bentley is shown round the control room of the plant there are modern LED light panels and modern health and safety stop buttons which would not have existed in the 1960s.
Factual error: Gently and team shine a maglite torch into an underground chamber. The episode was set in 1970. Maglite torches weren't manufactured until 1979.
Factual error: The Daimler DS420 limousine seen in this episode has a C registration which dates it to 1965 these cars did not start production until 1968.
