“OSS,” Amy muttered. She did a quick word search. The Office of Strategic Services was the spying arm of the American government during the war!

Amy clicked back to the research Evan and Ian had sent. Professor Hummel had turned out to be one superbad Nazi. He’d risen to major and had been involved in a group called the Einsatzstab Reichsleiter Rosenberg, which, as Evan put it, was quite a mouthful for “dirty despicable thieves.” They were also known as the ERR, Hitler’s special group that stole art and artifacts and property from Jewish families. The artworks were shipped to Paris and stored at a museum called the Jeu de Paume. There, the art was cataloged, inventoried, and crated, then sent to Germany. Hundreds of thousands of looted treasures from world-famous artists: Leonardo da Vinci, Michelangelo, Rembrandt, Van Gogh. Hummel was a high-ranking officer in charge, valuable because of his knowledge of medieval art.

“So, Herr Hummel,” Amy murmured, “you were a thief.”

Near the end of the war, as the Allies began bombing German cities, the Nazis got nervous. They moved the art to salt mines and caves and castles in the Bavarian Alps. It all would have worked except for a few inconvenient facts. One: The Nazis lost the war. Two: In 1943, a section of the Allied army was formed called the Monuments Men. After the invasion they traveled with the front lines, charged with finding the artworks and returning them to their rightful owners.

“The Nazis were evil, but what made them so especially chilling is that they were really organized about it,” Evan had explained. “They kept records of everything they stole. So when the Allied armies moved in, they found everything – hidden caches of priceless paintings and artifacts… . If Hummel had the de Virga, there should have been a record of it. But there’s nothing. It’s another dead end.”