This work investigates the final weeks of the Third Reich to determine the precise circumstances surrounding the death of Adolf Hitler and the collapse of the Nazi regime. Hugh R. Trevor-Roper, an intelligence officer tasked by the British government to investigate Hitler's fate in 1945, utilizes primary source interviews with surviving members of the Führerbunker and captured documents to reconstruct the chaotic final days in Berlin. The book argues that the disintegration of the Nazi state was a result of internal power struggles, delusional leadership, and the inevitable military defeat by Allied forces.

Historians widely regard this work as the foundational text for understanding the end of the Nazi regime due to the author's unique access to witnesses immediately following the war. Readers frequently note the meticulous detail and the clinical, investigative tone maintained throughout the narrative.