Yanek is a ten-year-old Jewish boy living in Kraków, Poland, at the onset of World War II. As the occupation forces his community into a restricted ghetto, he transitions from a sheltered child to a young adult who must mature rapidly. Determined and observant, he relies on the differing advice of his family members to maintain his identity and humanity in the face of increasing oppression.

Yanek's father is an inherently hopeful man who tries to believe the war and occupation will end quickly. As the Nazis tighten their control over Kraków, he continuously offers comforting words to boost his family's morale. He takes active steps to protect his son, including organizing a secret bar mitzvah in an abandoned warehouse to ensure Yanek comes of age according to Jewish custom.

Uncle Moshe is a highly pragmatic and realistic member of Yanek's extended family. Unlike Yanek's father, he understands the severe threat the occupying forces pose and accurately predicts the deteriorating situation. He advocates for prioritizing self-preservation above all else, advising Yanek to remain invisible and anonymous to avoid attracting the attention of the guards.

Amon Goeth is a vicious Nazi guard who oversees the prisoners with extreme cruelty. He treats the lives of the Jewish prisoners as a game, committing random acts of violence purely for his own amusement. His arbitrary brutality establishes the standard of terror that defines the oppressive environment the prisoners are forced to endure.

Yanek's mother is a resident of Kraków whose life is upended by the restrictive new laws and home invasions. Terrified by the constant raids on their apartment building, she seeks safety by moving her family into a hidden pigeon coop on the roof. She quietly uses her sewing skills to conceal money inside her family's clothing, preparing for an uncertain future.

Fred is a young prisoner around the same age as Yanek who grew up in the same neighborhood back in Kraków. He becomes Yanek's closest companion in the camp, providing a vital human connection in an otherwise isolating and brutal environment. They work, eat, and stand at roll call together, relying on each other for emotional fortitude.

Uncle Abraham is a relative of Yanek who owns a bakery in Kraków. Because his baking skills are useful to the Nazis, he is permitted to keep his business open to bake bread for the soldiers. He bravely uses his position to secretly bake and sell bread to starving Jewish families under the cover of night.

Moonface is a physically intimidating Nazi guard known for his sudden bursts of violence. He frequently assaults prisoners without reason, keeping them in a constant state of fear and submission. His erratic behavior epitomizes the senseless cruelty the guards inflict on the camp populations.