A few days after Kana's death, things seem to be back to normal for Shinichi. Satomi and her friends are perturbed by his seeming indifference, but Shinichi, himself, is grappling with his own sense of disquiet with his unnatural state of mind. Meanwhile, a man begins snooping around about Shinichi...

Shinichi's secret becomes known to Kuramori, the private investigator hired by Tamura. Shinichi tries to confide in Satomi, but his unsuccessful attempt only drives a wedge between them. Shinichi recruits Uda's help to break the impasse.

Though still full of doubt, Kuramori has, for the time being, accepted Shinichi. Soon after, Kuramori's resolve is severely shaken by witnessing a parasite murder a human being. Shinichi is frustrated by the turn of events, but the lull is cut short when a new parasite appears...

The newest parasite to appear is different from the others. Chatty and expressive, the parasite identifies himself as Miki and immediately makes his move. With Migi asleep, all Shinichi can do is to run and keep running...

Having determined Tamura to be a threat, Kusano's group moves to eliminate her. Meanwhile, Kuramori moves to avenge his family's death by abducting Tamura's baby. With her baby in his arms, Kuramori faces Tamura and threatens to throw the infant down a steep slope--what will Tamura do?

Shinichi and Migi arrive at the park, only to find Tamura holding her child. As Shinichi struggles to quell his fury at the sight of her, Tamura unleashes a flurry of questions about the meaning of the parasites' existence and what humanity means to them.