The narrative of Ruby Moon takes place in the fictional Australian suburb of Flaming Tree Grove. The set is designed to represent "a timeless, placeless world", with the action moving fluidly from the street to the interior of homes on a cul-de-sac. 

Coordinates are given for Hawthorn in the inner suburbs of Melbourne. This choice is based on playwright Matt Cameron's imagining of the setting. "Overwhelmingly the street felt to me like a street that probably looks picture-perfect during the day but at night suddenly becomes frightening and portentous. I grew up in the sad, bare outer suburbs [of Melbourne]. This particular image, though, was probably more inner suburban with old deciduous trees, a really established suburb." 

(http://australianplays.org/assets/files/resource/doc/Ruby_Moon_Matt_Cameron_Interview.pdf)

The interior and exterior spaces in Ruby Moon are not distinct from one another. The set and plot intentionally blur the action as it moves from space to space. The presence of the exterior street- the dead-end street- pervades all interior action, with characters constantly looking outwards, at the street, at the night, for Ruby.