Of the sixteen YoRHa androids who landed on Earth to recapture it from the enemy machine lifeforms, only four have survived the descent. Command denies their request to have their mission cancelled, however, leaving them stranded on Earth with no choice but to attempt to carry out an impossible mission. Immediately beset by the machines, the YoRHa units are saved by the appearance of another group of android survivors from a much earlier war. Though the older androids are suspicious of the newer ones, an uneasy alliance is forged. But this tenuous peace is about to be put to the test now that buried secrets are coming to light...