As the number of mincemeat murder victims grows, Shinichi, alone in his knowledge of the truth, is in turmoil. When Migi suddenly alerts him to the presence of another parasyte, he is aghast to find that it is in his own school. Paranoid, Shinichi attends a schoolwide assembly, where the staff introduce a beautiful new teacher...

Thinking he'd found his mother's killer, Shinichi instead meets Uda Mamoru, a man in a similar situation as himself. Uda sympathizes with Shinichi and suggests that they all work together. The time to avenge his mother has come at last! Shinichi heads to the precipice...

Yuko is drawn to Shimada Hideo, but gradually realizes that something is seriously amiss with Shimada's face itself. As Yuko pursues Shimada's secret, she connects the dots between him and her brother's police investigation.

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...

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...

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?

The joint operation by the police and the strike force to eliminate the group of parasites led by Hirokawa has begun. Yamagishi's unit uses their special sensor system to hunt down the parasites. Amidst the chaos, human victory seems all but confirmed. But the tables are about to be turned by a single parasite...