In the original script, Leela was to scream when overwhelmed by the gas. Louise Jameson declined to do this, pointing out that it was out of character for Leela.
All four episodes of the serial ran short of their allotted running time, forcing the use of extended and repeated shots for padding. This episode in particular was so much in need of padding that the reprise was much longer than usual.
This episode was watched by 9.1 million viewers on its original transmission.