Shu enters his hideout for a quiet lunch only to find Inori, his #1 musical crush, bleeding on the floor. After he fails to stop her pursuers from hurting her more, his one shot at self-respect is to deliver a strange vial she stole to her terrorist pals.

Yahiro reappears with Jun, who's in Stage V Apocalypse disease and can no longer battle the cancer. With Gai out of town, Shu's left to make a command decision. But he AND the enemy are about to learn the virus doesn't work the way they think it does...

Discontent within the ranks of the school is reaching fever pitch as the Exodus approaches.

The Fourth Apocalypse is upon us.