Rim was a human colony world of the 2170's overrun by a Xenomorph outbreak ten years before the Earth Infestation a family exploring the crash site of a downed alien spacecraft returned to the Rim colony with a medical emergency. The father who had discovered a clutch of alien eggs had been infected by a Facehugger the creature gestating inside him son hatched, quickly spreading the Xenomorph infestation though out the colony.