Features two actors who later appeared in the 21st century series Extra played the small plau who has a speaking role in Listen (2014). Mike Mungaravan was a extra in David Tennant first story.
This episode was watched by 4.6 million viewers on its original transmission.
About midway through this episode, two Mogarians are seen briefly playing a version of the 80's video game Galaga on a double-sided screen. BBC micro computers were used in the production during this era. The BBC micro port of this game was called Zalaga.