The year is 2073. 23 years after the world ended with the eruption of the Yellowstone-volcano. Not only did it saturate the upper atmosphere with ash, plunging the world into an unexpected ice age, but it also released something slumbering deep within the earth: an alien organism. Its spores spread all over the planet by the eruption, transforming large areas of earth into alien biomes, saturated with exotic mega-fauna and flora. The exotic radiation emitted by new rulers of earth turned these areas inhospitable to humans, who have been displaced to now walled off coastal or mountain-cities, reduced but not finished. Spearheaded by the UNs Aeon-program mankind slowly learns to utilize the invaders abilities, hoping to one day get the planet back under their control.