Tim Koeth peered into the crumpled brown paper lunch bag; inside was a surprisingly heavy black metal cube. He recognized the mysterious object instantly—he had one just like it sitting on his desk at home. It was uranium metal, taken from the nuclear reactor that Nazi scientists had tried—and failed—to build at the end of World War II. This unexpected gift, wrapped in a piece of paper inscribed with a few cryptic but crucial lines, would launch Koeth, a nuclear physicist and professor, and his colleague Miriam Hiebert, a cultural heritage scientist, on an odyssey to trace the tale of these cubes—two of the original 664 on which the Third Reich had pinned their nuclear ambitions.

From Werner Heisenberg and Germany's nuclear program to the Curies, the first family of nuclear physics, to the Allied Alsos Mission's infiltration of Germany to capture Nazi science to the renegade geologists of Murray Hill scouring the globe for uranium, the cubes are lodestars that illuminate a little-known—and hugely consequential—chapter of history.

The cubes are physical testimony to the stories of the German failure, and the successful American program that launched the world into the modern nuclear age, and the lessons for modern science that the contrast in these two programs has to offer.