Feb­ru­ary, 1939. In New York City, twen­ty-two thou­sand cheer­ing Nazi sup­port­ers pack Madi­son Square Gar­den for a hate-filled ral­ly. In a Hell’s Kitchen bar, Charles Moss­man is reel­ing from the loss of his job and the demise of his mar­riage when a group draped in Nazi flags barges in. Drunk, Char­lie takes a swing and a tor­rent of unin­tend­ed con­se­quences follows. 

Two years lat­er. Charles’s estranged wife and daugh­ter, Emma, live in a qui­et brown­stone in the Ger­man-speak­ing New York City neigh­bor­hood of Yorkville, where sup­port for Hitler is com­mon. Charles, just out of prison, strug­gles to put his life back togeth­er. Across the hall from his fam­i­ly, a kind­ly Swiss cou­ple, Tru­di and Willi Bauer, have tak­en a lik­ing to Emma. As the threat of war grows, and fears of a ​“fifth col­umn” — Ger­man spies embed­ded into every­day life — are every­where. When Pearl Har­bor is attacked and Amer­i­ca can no longer sit on the side­line, that con­spir­a­cy turns into a dead­ly threat with Emma as an inno­cent pawn.