The Nazis have invaded Hungary and war is raging in the main cities. To avoid it, a woman leaves her thirteen-year-old twin boys at their grandmother's place in the countryside. The children don't know their grandmother, a dirty, miserly, and mean old woman who barely allows them inside the house. Left to their own devices, the two children learn to cope with hunger, the cold, and the everyday cruelty in a devastated country. To protect themselves, the twins reject all moral codes and values and instead take their lessons from the evil around them in order to try to survive. The siblings studiously note, as objectively as possible, their discoveries and their burgeoning knowledge in a notebook.