In 1942, a rational fear was mounting that New York Harbor was vulnerable to sabotage. If the waterfront was infested with German and Italian agents then the US Navy needed a recourse just as insidious to secure it.

Naval intelligence officer Commander Charles Radcliffe Haffenden had the solution: recruit as his own spies, members of La Cosa Nostra. Pier to pier, no one terrified the longshoremen, stevedores, shopkeepers, and boat captains along the harbor better than the Mafia gangs of New York, who controlled the docks in Manhattan and Brooklyn. Haffenden was prepared to make a deal with the devil–the man who put "organized" into organized crime. Even from his cell in Dannemora State Prison, former Public Enemy #1, Charles "Lucky" Luciano still had tremendous power. Luciano was willing to wield it for Haffenden. But he wanted something in return—Luciano's contacts in Italy to track the Nazis' movements.

Operation Underworld is a tale of espionage and crime like no other, the unbelievable, first-ever account of the Allied war effort's clandestine coalition between the Mafia and the US Government to protect New York, vanquish the Nazis by taking the fight to the enemy in the 1943 US invasion of Sicily.