By the 22nd century, the United Earth Space Alliance had guided humanity into a lasting world peace and turned its full attention to space exploration. In 2147, the UESA launched a colony ship toward the asteroid Theta-2—but the follow-up vessel carrying the colonists was ambushed by alien ships emerging from a spatial anomaly that would become known as the Void. The fate of ten thousand people went unknown. In response, humanity built the inter-dimensional starfighter Radix and sent it through the Void to confront the alien threat.