Nobody can believe their eyes at the corpse that appeared from within Shiki's room. They try to figure out what happened, but the room was completely closed off, which only makes the plot thicken.

After the first murder, Shiki's uncle, Director Shindou, is killed as well. The lab is in an uproar. To find out who the killer is, Nishinosono and Saikawa investigate Shiki's room. There they find a robot named Michiru, and a strange message saying "Everything becomes F."

In the process of investigating Director Shindou's murder, Nishinosono and Saikawa learn the details of Shiki's multiple personalities and the murder of her parents that took place 15 years ago. The two of them try to figure out what she was thinking in order to find a clue. In doing so, Nishinosono is forced to confront her own past.