In the year 1999, a college professor addresses his assembled class of students, informing that it is time for the oral part of their final exam. He'll direct random questions to students and grade them immediately, and may direct the same question to other students. He tells them that he and the university board expect the students to continue their high level of performance. The professor begins with question son propulsion and physics. He continues questioning students until one of them, Johnson, fails to provide three of the four names required. When the professor tells Johnson to sit down, Johnson protests that he partially answered the question. The professor dismisses Johnson's responds, notes that the student is proving himself incompetent by questioning the professor's authority, and starts to threaten him with removal. Johnson quickly sits down.
After more physics questions, the professor informs them that the next part of the quiz concerns the behavioral sciences, which is considered the most important part of the college curriculum. He then calls upon a white student, Clinton, to describe a black student, Barnes, and asks how he would view Barnes as competition. Clinton soon points out Barnes' skin color and casually says that he may be inferior. The professor invites him to do what he feels is necessary, and Clinton steps forward and slaps Barnes in the face. The professor then tells Barnes to describe Clinton, and the black student describes the white one as bigoted and ignorant, and he should slap him. The professor tells him to proceed, which he does, and then confirms that both of them felt satisfaction upon assaulting the other.
Next, the professor quizzes Miss Peterson, asking her to choose a fellow student that she responds to in a negative manner. Peterson chooses Miss Fields and describes her as wealthy, upper-class, and snobbish. When the professor asks her why she feels that way, Peterson explains that she comes from a poor family. The professor tells her to proceed, and Peterson rips off Fields' expensive necklace and throws it to the ground. Fields responds by saying that Peterson is ignorant white trash. The professor tells her to proceed, and Fields picks up her necklace, gives it to Peterson, and then spits in her face.
The professor next chooses a male student, Elkins, and chooses him to pick out a potential enemy of the entire class. Elkins chooses William Chang, and the professor asks him to explain. The student says that there Chang is an outsider and that the group must kill to survive. The professor gives Elkins a gun and tells him to proceed. Elkins walks toward Chang, aiming the gun, but hesitates and finally shoots out the lamp behind his fellow student. The professor accuses him of missing on purpose, and Elkins admits that he did. Under the professor's interrogation, Elkins says that Chang isn't the group's enemy, and he won't kill someone without knowing why.
The other students, passive until now, start to respond. The professor tells his assistant Bruce to deactivate all of them before Elkins' "infection" spreads. The students stop and then go briefly into reverse before stopping for good. The professor, surprised at the students' resistance, tells Bruce to release Johnson. Johnson comes to life and the professor tells him to take the gun and explain the ramifications of Elkins' actions. Johnson explains that Elkins refused to kill the enemy and thus became the enemy himself. He then takes aims the gun and shoots Elkins in the head. The other students come to life and gather around Elkins: an android. The professor congratulates Johnson and gives him an A in the class.
Later, the Class of 1999 graduates and Johnson speaks at their commencement ceremony. He touches briefly on the fact that most of mankind has been wiped out by war, pestilence, and pollution, and that the "class" has been created to repopulate society, in Man's image. He assures his classmates that they have been taught to be just as ruthless and cruel as Man is to outsiders, allowing them to be men.