The tall foreigner living on Port Said Street in a Cairo hotel lived a simple life, reading books and writing letters, known as Uncle Tarek to neighborhood children. They did not know that he was actually Aribert Heim—the concentration camp doctor and fugitive from justice who became the most wanted Nazi war criminal in the world.Dr. Aribert Heim worked at the Mauthausen concentration camp for only a few months in 1941 but left a horrifying mark on the memories of survivors. In the chaos of the postwar period, Heim was able to slip away from his dark past. But certain rare individuals in Germany were unwilling to let Nazi war criminals go unpunished. Among them was a police investigator named Alfred Aedtner, whose quest took him across Europe and across decades, and into a close alliance with legendary Nazi hunter Simon Wiesenthal. This is the incredible story of how Aribert Heim evaded capture, living in a working-class neighborhood of the Egyptian capital, praying in Arabic, beloved by an adopted Muslim family, while inspiring a manhunt that outlived him by many years. He became the “Eternal Nazi,” a symbol of Germany’s evolving attitude toward the sins of its past, which finally crested in a desire to see justice done at almost any cost.