 He also emphasised that the episode is not solely about "having a laugh" with the sex gas, as it also has "something to say about the world".The scene where Carys walks down the street featuring sex in advertisements and couples kissing in public was one of Davies' favourite scenes in the episode, as it explores how the Western world is.The episode was originally much lighter in tone, however, the majority of the comedic moments had to be cut on the final script, as they got in the way of the plot.