Cendaphus (Planet)
Cendaphus is the third planet in the Great Simulation visited by Ariela Wolff in her quest to find more Mesh-capable sentients for the upcoming war against the Darkness.
It is inhabited by a race humans dub the "Greys", because they look reminiscent of the classical "Greys" beloved by human sci-fi:
The beings themselves looked something like the classical human depiction of alien Greys, though their skin was more brown, they had hair, and their eyes were not nearly as pronounced.
The planet has several continent-sized landmasses, but two in particular are close together, and during a glacial period about 25Kyr before present, sea levels dropped far enough to create a land bridge between them. This land bridge was quite important for the development of Cendaphus's Greys, because the race had originally evolved with a collective hive mind. However, mutations arose, creating Greys who were non-responsive to the hive mind -- they could still hear it, but they could resist it, to various levels.
The hive would kill any non-hive mutants out of hand, at birth if they could be discovered at that point, but eventually the non-hive got smart enough to evade detection and their community grew large enough to establish itself in the northern, less-hospitable portion of the Eastern Continent. Then, during the ice age, the non-hive community discovered the land bridge, and explored to the other side and beyond. They found a rich land completely uninhabited by other sentients, and migrated, lock stock and barrel, to the central part of the Western Continent, far out of reach of the hive collective.
Once the ice age ended, the oceans rose again and covered the land bridge. The collective on the Eastern Continent stagnated much as it always had, still killing off any non-hive individuals it could detect, and the non-hive race progressed like our Western world. At some point analogous to our Age of Sail, the non-hive race re-established contact with the collective. As had been the case before the migration, some of them were more affected by the hive than others when in close proximity. Getting those people out of the picture and back to where they were safe from control, they negotiated with the hive mind for resources, for which they'd trade finished goods and foods the hive hadn't managed to discover and cultivate. They also negotiated with the hive to take any mutants that might be born back to the West with them, offering a new solution to the old problem with which the collective had never really been comfortable dealing. Over time, other colonies of escaped, non-hive individuals were found, far to the north, and were offered free transit to the other side of the ocean; most if not all of them took the offer.
Fast-forward to the present day. Nothing has really changed to the East. To the West, the society of non-hive Greys has progressed through various ages and has now arrived in an Industrial Age, somewhat analogous to the 1950s on Earth. They are just beginning to implement atomic power, and they have added nuclear power generating facilities to their stock in trade; in the East, the collective is enthusiastic about ridding itself of the older coal and oil plants it had obtained from the West in decades prior.