Fall, 1942. In the midst of war, Special Agent Jimmy Nessheim has asked for extended leave from the FBI. Becoming a law student at the University of Chicago seems like the perfect way to re-enter normal civilian life. But the University of Chicago is home to more than an erstwhile FBI agent. Deep under the stands at Staff Field, renowned scientist Enrico Fermi is beginning work on what will become known as the Manhattan Project, research that could not only change the course of the war, but change the face of war itself. Perfectly placed to assist, Nessheim is persuaded by his superiors to return to duty to guard this precious research. Soon he begins to suspect a Nazi infiltrator has gained access to the project, and he must track down the traitor. Almost simultaneously, Nessheim's old flame Madison, an heiress with left-wing sympathies, finds him in Chicago. But is her reappearance a coincidence? Drawn once again into a web of international intrigue, Nessheim faces his most deadly threat yet.