Felix Kersten (1898–1960), a Finnish physician of Estonian origin, treated in Berlin during the Third Reich the most feared man in Nazi Germany, the head of the Black Order, Heinrich Himmler (1900–1945). Forcibly recruited by the SS, from 1939 to 1945 Kersten remained at the side of the most powerful man after Hitler himself throughout the Second World War beside the Minister of the Interior who first pursued the defense of the Aryan race through the Lebensborn project and later through the Endlösung der Judenfrage, the Final Solution of the Jewish Question.

In this position powerful yet precarious his intelligence and courage allowed him both to exert enormous influence over Himmler, leading to the release of tens of thousands of political prisoners and civilians, and to become, unwittingly, the first Allied spy inside SS headquarters.

On the Body of the Devil is not only a historical novel but a true spy story that penetrates the inner workings of Nazi power and reveals to a wide audience the story of a forgotten modern hero. It was only in the mid-1950s that a Dutch commission uncovered Kersten’s actions; many of those who had been freed then discovered that they owed their lives to the doctor. In 1960, Charles de Gaulle learned of the liberation of several French women thanks to Kersten’s intervention and decided to award him the Legion of Honour. Sadly, while traveling to receive the decoration that might have rescued him from the oblivion of European history, he died of a heart attack on April 16, 1960.