From the ashes of the Prothean Empire, one of the Reapers' greatest instruments turns against them. Though victorious, the galaxy is left almost beyond recognition. For countless millennium afterwards, the galaxy heals and regrows; however, the same could be said for the very creation the Reapers have banished. Without the Reapers, reenter the Neuroi.

When the strike witches are forced to flee from their home reality they alter the destiny of the Systems Alliance, and the entire galaxy.