In 1862 Union forces attacked Fort Pulaski (w a national monument), in the Savannah River. These forces, under the command of Captain (later, General) Gillmore, initiated a brutal bombardment of the fort from positions on Tybee Island. Now, some 150 years later, park rangers at Fort Pulaski national monument are astonished to find two rounds from a modern, tank-fired shell in the crumbling walls of the fort. Free-lance investigator David Mannering, native of New Zealand and former soldier of fortune, is brought in by the Smithsonian to investigate the find. Are the shells what they appear to be? If so, how did the come to be where they were found. Is the discover related to the mysterious disappearance of a National Guard tank during Tybee maneuvers? And what do the mysterious Pulaski Papers contribute to solving the mystery?