When first shown in the UK, large areas of the country missed the last few minutes due to a massive electrical blackout. The public outcry was so great that on one of the following days, the resolution was printed in national newspapers. However, many people felt that such a resolution wasn't good enough, and the broadcaster received an unprecedented number of complaints, prompting the episode to be repeated the following week.
Diana Dors had starred in a Hammer film, but not a horror, a film noir titled MAN BAIT.
Robert Urquhart co-starred in Hammer's The Curse of Frankenstein.