In a post-apocalyptic future torn apart by shadowy creatures, a tech-scavenger helps a mysterious girl discover the key to her identity, which could save the world.
Echo and Mu try in vain to evade the Earless as three mysterious women chase after them.
Familiar faces come to the rescue and Mu finds new facts about her core part.
Echo and Mu continue their journey to find Jimi and end up in Londinium; in Londinium, Mu is asked to participate in their plans for Christmas.