The students of class 3-E, whose teacher, Koro Sensei, has promised to destroy a large portion of the Earth unless someone kills him, have been infected with some biological agent. They infiltrate their enemy's lair, face down Smog, Grip, and Gastro--assassins specializing in poison, strength, and firearms--only to find that the Mysterious Mastermind, who wants to kill Koro Sensei himself and take the reward from the students, is someone they all know.

Printed Manga-style; book opens from left to right. Pages are read from right to left. Translation of: Ansatsu kyoshitsu. Originally published: Tokyo : Shueisha Inc., 2012.