The Celaeno Library in the Pleiades star cluster is home to the largest book collection in the universe. It’s said that even variants of Yiu-th only handed out at events can be found there. Mahiro is dragged along for some reason as Nyarko goes there to return a book. Hasuta, a former worker at the library, does his best to show Mahiro around, but they soon encounter two evil deities who have infiltrated the library…