In the middle of rewriting the universe by expanding her Labyrinth and altering her nemesis, the Incubator, Homura is approached by a strange creature that could easily pass off as a Familiar, if it wasn't for the fact this panicking hybrid of a Legless Crow with Butterfly Wings would separate into two clouds of smoke (one black, the other white), and turn into two teenage girls. Who were they ? What did they want ? And most importantly, were they going to be a nuisance fighting against her plan ?

Before AICO'S new story can begin, there must first be understanding from the characters of what they're about to face. Who better to serve as their mirror to the truth other than the toy who became human ? However, the godlike girl Lain doesn't understand the nature of human communication. And we all know what happens when she feels unable to communicate.