The events of the dam incident are shown, including when the Hojo family antagonized against the Sonozaki family and village residents. It is revealed that the dam construction manager was killed by employees when he sees them drinking after work and went on a rampage. Meanwhile, Takano and Irie had been researching the syndrome at the institute, but they needed a live specimen to prove the linkage between a parasite and the onset of the syndrome. They eventually utilized one of the construction workers (who were succumbed to psychosis) responsible for killing the construction manager as a live specimen. In another flashback, Satoshi discusses with Irie regarding how he wants Satoko to stay at the clinic longer than spending time their aunt, simultaneously lifting a burden off of himself. During all these events, Hanyū feels helpless and apologetic, but years later she and Rika eagerly await the arrival of the one person as the key to bring an end to the intention.