La Mort est mon métier presents the pseudo-memoirs of Rudolf Höß (renamed Rudolf Lang in the book), the notorious commandant of the Auschwitz concentration and extermination camp during World War II.

The story begins in 1913 when Rudolf Lang is just 13 years old. Raised in a misunderstood and highly normative Catholic environment, Rudolf's father, a merchant and military man, pressures him to become a priest to atone for his own past sins. Rudolf initially believes in God until a pivotal incident shatters his faith, leading to a strained relationship with his father.

As World War I erupts, a young Lang embarks on a military career, experiencing the harsh realities of war. After the war, he faces unemployment and family rejection, almost leading to suicide. Instead, he joins the Nazi party, eventually rising through the ranks to become the commandant of Auschwitz.

Under the orders of Reichsführer Himmler, Lang is tasked with the grim duty of exterminating 500,000 individuals annually. The camp evolves into a death factory, and Lang becomes a key figure in the Holocaust, overseeing the murder of millions.

Throughout the book, Lang is portrayed as devoid of personal feelings, driven solely by orders from his superiors. Even after the war, when imprisoned and sentenced to death, he claims he was merely following orders. The narrative concludes with Lang feeling betrayed by Himmler, who avoided accountability through suicide, leaving Lang to shoulder the blame.

This chilling tale offers a stark look into the mind of a man who played a pivotal role in one of history's darkest chapters, highlighting the psychological complexities and moral voids within.