The most common question asked by those who tour the Anne Frank House in Amsterdam is: “Who Betrayed Anne Frank?” 74 years after the Nazis’ tragic abduction of the residents of the secret Annex in August 1944, two Dutchmen decided to take on the unsolved mystery. Filmmaker Thijs Bayens and journalist Pieter van Twisk collected a team of some 20 experienced professionals: former police officers, journalists, war crimes investigators, forensic psychologists, historians, data scientists, and criminologists, with retired FBI agent, Vince Pankoke, serving as team leader. In the five-year long investigation, the team examined over thirty scenarios. Eventually, turning to a long-known piece of evidence, an anonymous note sent to Otto Frank shortly after his return from Auschwitz that identified the betrayer, the Cold Case Team concluded that the Dutch notary Arnold van den Bergh was the most likely perpetrator. When I was invited to write the story of the Investigation, I saw Van den Bergh as a tragic victim whose life was upended by the horrific military occupation of his country. My book offers a warning: there are uncanny parallels between the slow evolution of fascism in the 1930s and our present time when fanaticism, untruths and violence have become norms.