Helmuth is a seventeen-year-old German boy imprisoned on death row at Plötzensee Prison. Raised in a Mormon household in Hamburg, he starts out as a patriotic child who admires soldiers but slowly develops a deep hatred for the Nazi regime. He possesses a strong moral compass and is willing to risk his own safety to seek and share the truth.

Gerhard is Helmuth's smart, practical older brother who shares his sibling's Mormon faith and quiet disapproval of Hitler. Despite his personal misgivings, he believes in obeying the law and accepts his conscription into the military. He strives to protect his family and maintain order during a turbulent political era.

Hugo is a cruel and authoritarian Nazi paramilitary officer who eventually marries Mutti. He blindly absorbs and repeats government propaganda, deeply hating anyone who does not fit his narrow definition of a true German. He acts as an aggressive, unyielding disciplinarian within the household.

Mutti is the hard-working mother of Helmuth, Gerhard, and Hans. Seeking financial security and stability, she ignores the troubling realities of the Nazi regime and aligns herself with Hugo. She prefers to remain silent rather than confront uncomfortable truths or risk losing her comfortable life.

Brother Worbs is an elderly Mormon friend of Helmuth's family who boldly speaks out against the Nazi party. He refuses to censor his opinions, prioritizing truth over personal safety. His outspoken nature places him directly in the crosshairs of the oppressive government.

Rudi is one of Helmuth's best friends and a fellow Mormon. He partakes in amateur detective games with Helmuth before becoming involved in riskier activities. He is loyal but frequently worries about the severe consequences of defying the government.

Karl is a close friend of Helmuth and Rudi who was kicked out of his Hitler Youth platoon for fighting an aggressive leader. He provides a balancing voice of caution when Helmuth becomes too confrontational in public.

Hans is Helmuth and Gerhard's older brother. He grows up in the same household in Hamburg but features less prominently in Helmuth's daily conflicts than Gerhard.

Oma is Helmuth's grandmother, who lives next door during his early childhood. She is skeptical of Hitler's promises and openly worries about the future of Germany under his rule.

Opa is Helmuth's grandfather. He is an observant man who accurately identifies the threat Hitler poses to peace in Europe long before the war begins.

Gerhard Düwer is a young apprentice who quickly befriends Helmuth at work. He shares Helmuth's doubts about the official news and shows enthusiasm for pushing back against the government's narratives.

Werner is a fellow apprentice at Helmuth's workplace. When Helmuth attempts to gauge his willingness to help translate materials, Werner responds with suspicion and hostility.

Herr Mohns is Helmuth's boss. He is a strict man who enthusiastically supports the government and believes in reporting suspicious behavior to the authorities.

Herr Vinke is a middle school teacher who aggressively promotes the new nationalistic thinking. He punishes students who question the logic of blindly sacrificing oneself for a flag.

Herr Zeiger is an antisemitic teacher who verbally attacks his Jewish students. He actively indoctrinates his classroom with government prejudice.

Herr Meins is a teacher who privately compliments Helmuth's writing ability while subtly warning him to hide his idealism. He appears to harbor private disagreements with the ruling party but keeps them hidden.

Benno is a Jewish student in Helmuth's class whose father is a decorated veteran. He faces severe harassment from both students and teachers before being forced out of the school entirely.

Herr Seligmann is Benno's father and a proud German veteran. He is violently assaulted by storm troopers outside his shop, an event that deeply disturbs young Helmuth.

Franz Seeman is an unemployed man whom the boys report to the police for speaking with a murder victim. The swift and potentially baseless punishment he receives makes Helmuth question the justice system.

Inspector Becker is a police officer who tasks the boys with an open murder case. He is quick to jump to conclusions, jailing a suspect primarily for being unemployed.

Müssner is a violent Gestapo officer tasked with interrogating suspected traitors. He uses extreme physical force to extract information and confessions from prisoners.

Justice Fikeis is a furious, high-ranking judge who presides over cases at the Blood Tribunal. He is unyielding and demands absolute faith in the government's impending victory.

Herr Ranke is the Executory Leader at Plötzensee Prison. He oversees the administrative procedures for death row inmates and processes their final requests.