"Daniel Half Human" is a fictional account of Daniel Kraushaar, a German teenager who is caught up in the rising Nazi movement in the 1930s until his life is turned upside down by the revelation that he has Jewish ancestry. Daniel lives with his affluent parents Rheinhard and Sophie in Hamburg. His father is a prominent attorney and decorated World War I veteran while his mother is the daughter of Jewish parents who have never belonged to the Jewish community. Daniel and his best friend, Armin, dream of one day joining the Hitler Youth and are arrested one night for painting Nazi slogans on buildings.

Both boys attend a prestigious school, which begins to teach racial theories of Aryan supremacy and Jewish inferiority after Hitler comes to power. Daniel, who only recently has learned that he is half-Jewish, conceals his ancestry while other Jewish students are expelled from the school. His secret is eventually exposed. However he is allowed to stay on at the school out of deference to his father, a prominent German. As the Nazis consolidate their influence and pass anti-Jewish laws, Daniel is persecuted more and more by his schoolmates and ostracized by his teachers.

Matters become even more tense when Daniel's cousin, Miriam, who has been raised Jewish, comes to stay with his family after her father is imprisoned for his socialist political beliefs. She takes up a relationship with Armin, who has now joined the Hitler Youth and has to see her secretly. Armin is also told that he cannot associate with Daniel.

Daniel's father is forced to abandon his law practice and the family must move from their large comfortable house to a cramped apartment. Daniel's father refuses to consider leaving Germany or allowing Daniel and his mother to leave. He is certain the Nazis will not retain power and their persecution will end.

When Armin's relationship with Miriam is discovered by his superiors, he is told that he will be given a chance to make up for his transgressions. Fearing that Daniel and Miriam are in danger, Armin warns them. They escape and hide during the night of November 9th, 1938. This is the night when Jewish businesses, homes, and synagogues are smashed and burned by the Nazis.

Daniel and his parents are fortunate enough to leave Germany and go to America. Daniel becomes an interpreter for the British Army and is stationed in Hamburg, near the neighborhood where he had grown up, which has been flattened by bombs. While interrogating German officers after the war, Daniel meets again with Armin, who has been captured. Although he has an opportunity to allow Armin to be released, Daniel does not help him.