When the Science Council declares that Energo Limited, an energy company, must stop drilling for a rare type of Geo-thermal energy it is up to Mysta to step in when the company defy the ban and continues their exploitation in private. To make matters worse subterranean natives take advantage of Energo's explorations and use the harnessed volcanic activity to threaten the surface world by destroying cities and returning the Earth to a natural state.
The Robot makes an appearance but Bron is nowhere to be seen. Being made of sinew and without the benefit of Mysta's super-science, the human 'assistant' doesn't have much to do in this chapter due to the hostile environment of the underworld. Presumably left behind in safety on Mysta's extraterrestrial science-fortress the homo-phonically named Bron, nearly a prisoner, must wait for his mistress to return.
It often becomes necessary for the reader, particularly with the format of the Golden Age comic book, to fill in the desired details that the decompressed style of telling a story will skip or leave out. Politics and greed are fine plot devices but no one reading these stories really cared about the day-today details of running a large metropolitan city and government. Seven pages does not leave a lot of room for characterization when action fighting deformed criminals and bug-eyed monsters is required to bring a reader back the following month. So it is the relationship between Mysta, the robot, and Bron is one that would be understandably complex and mature and if published today would require years to tell. Subtext of the Golden Age far outpaced even Silver Age DC or 1970s Marvel for allowing a reader to imagine their own deeper meanings to a tale.
In Millennium author John Varley cast the robot/android assistant to the futuristic heroine as an all-purpose aide that not only acted as lab equipment, secretary and confidant but as a sex companion as well (something that did not make the transition to the film). Coincidentally, there are more than a few parallels between Varley's work and Mysta. Isolated, futuristic science-heroine with difficulty relating to people, a demolished civilization and people on the brink of extinction, even a somewhat self-sabotaging Science Council that creates as many problems as they solve. Another aspect of Mysta that mirrors Varley is the emotional abandonment of the robot once the brawny meat-puppet makes an appearance. Yet as far as Mysta goes expounding on her relationship with her lab assistant can veer dangerously into fan-fiction. So barring Image Comics publishing a chapter of Mysta of the Moon for their Next Issue Project it is best that anyone wanting a greater depth to her story just pick up or download a copy of Millennium and where ever the names Louise Baltimore or Bill Smith appear just mentally edit them in their place to Mysta and Bron.