First Referenced:
'I was told that everyone I'd served with in the military died shortly after I left. (Part 5)'
The Branch Worlds are parallel realities, which appear to have been derived from and grown by the Brownshirts while assisting The First World in building the fortifications of the Inner Shield and Outer Shield. These realities serve to disperse forces exerted on the two shields and provide structural support, similar to the supporting structures within any typical building.
The Branch Worlds are classified as being read-only, and little is known about the Branch Worlds, other than that a number of them also support the vast machinery required to generate and maintain the two shields. Heath is able to read information from the systems within such realities which has shown that the inhabitants are currently safe from The Crushing Fist and its effects, however there is currently no way to project information into these realities.
Since the destruction of The First World, at least one Branch World has suffered damage to the shielding that ensured it was read-only. As a result, electromagnetic radiation (radio waves) have begun leaking out, signifying that transit to the reality within may now be possible.