Two years after Nezumi left No.6 with a promise to return, Shion now chairs the city's Reconstruction Committee, caught between political instability and an unidentified killer striking at random and closing in on him. Overwhelmed and worn down, he can't stop thinking about Nezumi, until one day he senses him somewhere close by. This sequel novel picks the two of them up where the original series left off and asks whether they can still build a world in which no one is trampled.