Scenes of Doyle's surgery were filmed at the Royal Free Hospital, London. Among the uncredited extras playing the surgical staff is real-life surgeon and intensive care expert Professor Julian Bion.
Filmed in October 1980 but not transmitted until December 1982, over two years later.
The Bible quote Bodie makes to the pure . . . " is actually in its entirety : "Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled." - Titus 1 : 15.