The story's protagonist is Andrea Marescalchi, a passionate and attentive high school teacher, the sole survivor of the massacre committed on the day of his final exams by Vitaliano, his most difficult and beloved student.
The sole survivor of the exam commission, Professor Marescalchi will be forced to question the reasons for that final and unjustifiable act and whether Vitaliano, by allowing him to live, truly spared him or, rather, condemned him to question the reasons for his survival.