Back When You Called Us Devils Vol. 9 (Kodansha, 2022)

Nobody needs to be unhappy any longer. Striving to live up to his credo, Detective Shibasaki makes contact with Yusuke, a certain theory in his mind. Soon he learns the truth behind the two bodies found by the dam. As the story heads toward ultimate destruction, another life finds itself reaching its wretched, vain end...as another so-called ""devil"" enters the scene.