It is 1930, and ground has just been broken for the Empire State Building. One of the thousands of men who will come to work high above the city is Michael Briody, an Irish immigrant torn between his desire to make a new life in America and his pledge to gather money and arms for the Irish republican cause. When he meets Grace Masterson, an alluring artist who is depicting the great skyscraper's rise from her houseboat on the East River, Briody's life suddenly turns exhilarating--and dangerous--for Grace is also a paramour of Johnny Farrell, Mayor Jimmy Walker's liaison with Tammany Hall and the underworld.