It's a story that could have been lifted from a Dan Brown novel: When Profesor Koeth enters his office at the university of Maryland one foggy morning, he finds a mysterious gift on his desk. The cube-shaped surprise weighs heavy in his hand. It is wrapped in a brown paper napkin and a note is attached to it: "Taken from Germany, from nuclear reactor Hitler tried to build. Gift of Ninninger." Koeth unwraps the gift. He cannot believe his eyes at first. Is it a real uranium cube? And does it really stem from an old German nuclear program? If so, how did it end up in his office 70 years later? In Hunting Hitler's Bomb, Koeth and his German counterpart, Dr Nagel, embark on a treasure hunt that stretches half around the globe. Did Koeth's cube truly come from Hitler's efforts to build a nuclear bomb - and are more cubes out there? We're about to find out.—National Geographic