Based on a current BBC TV series in production, it uses four of the regulars from the show though largely sidelines them in featured rôles, favouring new character Del Shaw (played by Ian Bannen, whom director Peter Sasdy knew socially) as the lead alongside Judy Geeson's local schoolteacher, who aids him on Balfe Island.
Simon Oates was working elsewhere when the film was mooted, and originally turned it down. Tigon came back to him with a larger pay offer, and he agreed to feature. He was later dismissive of the film, feeling he had accepted more out of financial consideration than artistic merit.
One of 13 titles included in Avco Embassy's Nightmare Theater package syndicated for television in 1975, and the sole British one.
Del's samples from Balfe are dated to [Wednesday] 20th - [Thursday] 21st October 1971.
During the shoot, Peter Sasdy was hugely entertained by sitting with George Sanders in his dressing room, listening to his Hollywood anecdotes.