December 1939. Nighttime Manhattan. Snow mixed with rain. Two shots ring out in an alley. Max Grant, private investigator, two double bourbons under his belt, enters the alley to investigate. A man, two bullets in his chest, dying, paws at his coat pocket. His only words are, "Find the nude on the cigarette case." Grant removes the cigarette case, looks at the picture, pockets it, then calls to bystanders to get the police. Curiosity, even without a client, prompts him to investigate and leads him into the murky sphere of activity that surrounds the beginnings of the atom bomb.
The war in Europe is public, but something else was going on, quietly, behind the scenes, never making headlines in major newspapers or news programs on radio. Walter Lippman doesn't write about it and Edward R. Murrow never mentions it in his CBS news broadcasts. That something is the exchange of nuclear fission information between mathematicians and physicists in the Unites States, England, and Europe. In 1939 that information exchange has diminished in volume between the western scientific communities and those under German control and influence, most notably Denmark and Norway.
Sarah Bennett, the nude on the cigarette case, has been kidnapped and is being held in the Redhook area of New York by German agents. Bennett, a scientist, travels Europe under the guise of an art dealer but is also the conduit for shared information between scientists in Nazi dominated Europe and those in the United States. And Max Grant, in love with a photo on a cigarette case, is just the guy to go looking for her.