Strange occurrences at sea result in Itogami Island becoming isolated. Nagisa continues to suffer effects from her previous exertions. A terrorist group known as Tartarus Lapse begins operations on the island.

The terrorists launch an attack upon the warehouse district. Afterward, Kojo and Himeragi meet the terrorist leader, Senga Takehito, who tries to recruit them. He reveals his beliefs about the true nature of the island, its purpose of reviving Cain, and his plans to oppose this.

At Mogwai’s urging and with Motoki’s assistance, Asagi makes her way to the Keystone Gate in order to end the hacking attack upon the island’s network. Meanwhile, Kojo and Himeragi battle ineffectively against the demons unleashed by the terrorists.

After the terrorist incident on Itogami Island, Kojo and the others are helping with the Island's recovery. On the other hand, Asagi, who gained popularity with the public for preventing hacking in the past incident, works as an ambassador for revival activities for the Island Management Corporation. However, Kojo feels like something is off when he sees Asagi on the big screen.