HP Lovecraft, Nyarlathotep
The galaxy has been, for billions of years and at all scales of power, perception, intelligence and activity, overrun with life. The geometry of reality gives spontaneous rise to minds and organisms, and they beget infinite variations of their kinds. Escaped experiments learn to breed, autonomous systems outgrow and abandon their creators, patterns self-select and iterate into extinction, ‘gods’ billions of years old delineate a living space in lesser minds, time and mutation turn every individual into an ecosystem, and always, new and ancient races build and fight and die.
Earth is no exception.
after At the Mountains of Madness:
The Starkweather-Moore expedition recovers the Miskatonic antarctic expedition, and with them, the ancient city, its frozen inhabitants, and the secret origin of humankind. Despite attempts at secrecy, rumors, descriptions, and eventually images of the city make their way into the public eye. Still, skepticism rules, especially after the failures of subsequent expeditions.
What the public doesn't know is that a secret expedition was made, and eleven of the frozen "Elder Things" have been transported back to the USSR and carefully revived. With no other apparent options, the relatively genteel ancient beings resign themselves to tutoring their strange spinoffs. The USSR begins making strange jumps in the fields of cognitive science, hypnosis/subliminal messaging, AI, and biological enhancement.
after Shadow Over Innsmouth:
The raids on Innsmouth and Devil's Reef inspire a government conspiracy to investigate and counter the threat of the "Deep Ones". This conspiracy wages a secret war, and striking at the deep ones in their cities with underwater atomic "tests". The scattered survivors strike back against islands, coastlines, and ships. Coastlines must be either fortified or abandoned, and every sailor learns to keep weapons close to hand. The secret war continues.
all the while:
The "Mi-go", who for so long have secretly exploited the resources of Earth, are alarmed by the sudden acceleration in human science and technology. Unwilling to abandon even a backwater mining colony, they resolve, in a careful and peculiar manner, to engineer the extinction of the human race. Mi-go priorities are first, to eliminate the emerging threat of humanity, second, to remain hidden and unknown to their victims, third, to preserve Earth's resources for exploitation, and fourth, if possible, to preserve humanity for study and exploitation. Therefore they do not invade, assault, or bombard, but begin engineering Earth's biosphere into a hostile force.
The year is 2001. The remnant nations of the 20th century maintain themselves with the aid of the United Nations Sustained Emergency Committee (UNSEC). The rest of humanity resides in collectives, city-states, cult towns, and anarchies both deliberate and desperate. Earth is an alien planet, we are stranded, and adaptation might be worse than extinction. It is the beginning of the Strange Aeon.
Strange Aeon is my take on a world where humanity spent the 20th century coming face-to-face with a Lovecraftian universe, and flounders in ever more social, scientific, and even metaphysical chaos. Every day there is a new cult, disease, or monster, and the world passes steadily beyond the human .
Think of it as CthulhuTech, with a re-imagined Lovecraftian mythos, but replacing the anime influences with, among others, Charles Stross' A Colder War, Arkady and Boris Strugatsky's Roadside Picnic, and David Gerrold's The War Against the Chtorr.