Otto von Wächter was an Austrian Baron who joined the local Nazi Party before it was popular or profitable – by the age of 21 he was already protesting in Vienna, calling for Jewish rights of citizenship and property to be abolished. He graduated to the SS, and served as Governor - Brigadeführer - in Krakow and Galicia (now the city of Lviv, Ukraine) during the war. The area saw its entire Jewish population forcibly shifted to ghetto and camp. The lost included Philippe Sands’ grandparents, a tragedy covered in his previous book, East West Street.

Von Wächter’s son Horst prompts Sands to investigate his father’s story, stubbornly holding on to the notion that Otto was an honourable man. A beloved, if wandering, husband and a proud Dad he might have been, but Horst, perhaps understandably, seems blind to the sins of his father, and his mother too for that matter, who “completely despaired” at the Jewish population, enjoyed sowing swastikas into clothes, and wasn’t averse to plundering the art collections of the conquered. While Sands develops a fondness for Horst, he presents the facts as they are, aided by the younger Von Wächter’s family records. To point to just one piece of evidence, Otto’s seeming annoyance at having to have 50 Poles publicly shot leaves us in little doubt about the close proximity of blood to his hands.

Von Wächter eluded capture after the war, escaping first to the Alps, then ending up in Rome, where the plan was to skip to South America along the Ratline escape route of the title. Though under the protection of Alois Hudal, an Austrian Bishop who had praised Hitler as far back as his 1937 book, The Foundations Of National Socialism, Otto wasn’t as fortunate as Eichmann or Mengele, and never made it to Argentina. Instead, he died in The Eternal City, somewhat suspiciously, after being deposited in a local hospital under the name of Alfredo Reinhardt. Horst hopes Sands can uncover proof of foul play, but his belief in a Russian poisoning plot proves unfounded.

Nazis on the lamb, American and Russian agents in post-war Rome as the Cold War dawns, Vatican foul-play - how could a story like that be anything other than riveting? Marvellously told by Sands, this is history as a page-turning detective thriller.