Duel was watched by 10.0m viewers.
Duel was the seventh episode to be made but was always planned as the eighth episode in the run.
Camfield ran out of time and some scenes were not shot on location. They were recorded in studio against a CSO backdrop. CSO was also used for the appearance and disappearance of Sinofar and Giroc.
Studio recording took place in Studio TC6 at BBC Television Centre from Mon 9 Jan, 1978. Spacefall was broadcast that night.
Terry Nation's original script referred to the alien planet as Amersat. The Mutoids were originally referred to in the scripts as Androids, human machines running on blood.
Broadcast: Monday 20th February 1978: 7.15pm-8.10pm, BBC 1
Writer: Terry Nation
Director: Douglas Camfield
"Blake is sitting up in a tree, Travis is sitting up in another tree. Unless they're planning to throw nuts at one another, I don't see much of a fight developing before it gets light." Avon
RADIO TIMES: The fleet of Federation pursuit ships commanded by Travis finally succeed in trapping the Liberator.
GUEST CAST: Isla Blair (Sinofar), Patsy Smart (Giroc), Carol Royle (Mutoid)