The right to command Akashi and company after their return from Yomijima was handed off to Suzaki. Kasane, who wants to solve the mystery behind the Lightless Stone, heads to the abandoned hospital in search of materials left behind by Natsuiri. However, during her search, an Admonition attacks. Akashi heads to rescue her aboard the Argent, but Kasane could feel nothing but uneasiness at its unnatural resonance rates.

読島から戻ったアカシたちの指揮権は須崎に譲渡されることとなった。無明石の秘密を解き明かしたいカサネは、夏入が残した資料を探しに廃病院へと向かう。しかし、探索中にイマシメが強襲、アカシがアージェントで救出に向かうが、その異常なまでの共振にカサネは不安を感じずにはいられなかった。