After their humiliating defeat, the crew of the USS Missouri decide to lay low. However, before they can do so, the USS Ermiana arrives, giving them supplies and intel that suggests that I-400 is planning to create a synthetic body for herself, and thus assume an "ultimate form."

The crew of the Missouri realize that if I-400's plan comes to pass, it would spell grave news for the denizens of the galaxy. And so, the race is on to retrieve the synthetic body from I-400's clutches. Along the way, two former adversaries will become reluctant allies after they discover I-400's true plan to bring about galactic extinction.

Another potential ally could lie in the synthetic body itself, partially uploaded with the conscience of the Iona interface, revealed to have survived I-400's attack. But is this new form, who calls herself "I-402" as she is neither I-400 nor Iona, really on the side of life as she claims?