Back to Sid's filmography: Following explorations in the Far Country, it was thought that forging a connection between Gaping Gill and Ingleborough Cave was close, and Sid Perou persuaded the The World About Us producer to fund a program that would document the link up. The thrust of the film was documenting the diving activities between Terminal Lake in Ingleborough Cave and Deep Well in the Far Country. Cavers featured include cave divers Mike Wooding and Tom Brown; cave guide Bob Jarman; Eric Hensler recreating his famous explorations; and Mel Gascoyne, Alan Proctor, Ian Macgregor, Mark Parker, and Dave Checkley from Lancaster University Speleological Society in support. The film was first broadcast on 15 August 1971 on BBC Two and was an hour long. This is a cut-down version which was broadcast in 1984 in conjunction with the breakthrough film.