Set in the years 1925 to early 1933, the novel tracks O'Hara, Gantt, Tolson, Sawyer and Jordan through new trials and tribulations. The rift between old friends Declan O'Hara and Aloysius Gantt deepens, with O'Hara pursuing criminal cases from the nation's capital to Oklahoma and New Jersey, while Gantt defends his ties to Edgar Hoover against recent newcomer Clyde Tolson. 

Third classmate Greg Jordan, now attorney and consiglieri for his brothers' crime family in New York City, finds himself in the midst of the Mafia's bloody Castellammarese War, forced to take violent personal action in defense of his loved ones. 

Isaac Sawyer, cashiered from the Bureau of Investigation for the color of his skin in 1924, makes his mark with the Treasury Department's Prohibition Unit, then transfers to the fledgling Federal Bureau of Narcotics when President Herbert Hoover shifts Prohibition enforcement to Justice, back under Edgar Hoover's thumb. The FBN's mission takes him from Manhattan's Chinatown to Texas in pursuit of dangerous drug smugglers. 

The sudden death of Thomas Walsh, named as the next U.S. Attorney General, rescues Edgar Hoover from enforced retirement, while prompting Declan O'Hara to wonder if there might be more behind that death than just an unexpected heart attack.