Xenoblade Chronicles X opens as humanity, warned of its impending destruction in the crossfire between two warring alien races, constructs interstellar arks to escape Earth. However, only a few arks escape the destruction, including the White Whale ark. Two years after launching, the White Whale is attacked and transported to Mira. During the crash-landing, the Lifehold—a device containing the majority of the human colonists—is separated from the White Whale, with lifepods containing colonists being scattered across Mira. The avatar is awoken from a lifepod by Elma and brought back to New Los Angeles. While suffering from amnesia, the avatar joins BLADE, working with Elma and Lin to recover more lifepods and search for the Lifehold. During their missions across Mira, BLADE encounters multiple alien races, learning that those attacking them are part of the Ganglion coalition, an alliance of races led by the Ganglion race, who are intent on destroying humanity.
