Scientists have always kept secrets. But rarely have the secrets been as vital as they were during World War II. In the middle of building an atomic bomb, the leaders of the Manhattan Project were alarmed to learn that Nazi Germany was far outpacing the Allies in nuclear weapons research. Hitler, with just a few pounds of uranium, would have the capability to reverse the entire D-Day operation and conquer Europe. So they assembled a rough and motley crew of geniuses - dubbed the Alsos Mission - and sent them careening into Axis territory to spy on, sabotage, and even assassinate members of Nazi Germany's feared Uranium Club.