An FBI investigation of a German spy ring on American soil threatens to devastate lives, loves, and families forty years after the end of World War II   A watertight packet is discovered by a diver in the waters surrounding Block Island. Unrecovered detritus from the last German U-boat sunk off the coast of Rhode Island, it contains secret codes suggesting that a Nazi spy ring operated in the United States during the darkest days of World War II. If confirmed, it could prove a major embarrassment to the FBI--whose late director, J. Edgar Hoover, once assured the government there were no spies in the country--so the Bureau sends one of its best, Unit Chief Todd Oliver, to Newport to investigate.   A war that ended four decades earlier is not yet over for some in this New England naval town, as Oliver's mission threatens to destroy the lives and relationships of the guilty and the innocent alike. Suddenly, dark, lingering shadows are everywhere, enveloping respected pillars of the community, the wealthy and powerful in their mansions on "the Avenue," and respectable, law-abiding citizens who merely wish to forget. Even Oliver himself is not safe, as the agent's inquiries into secret wartime espionage begin unraveling strong, sacred bonds of love, friendship, and family, tempting the dedicated operative to compromise everything he stands for in the face of a shocking murder that rocks Newport society to its core.