On October 2, 1918, Maj. Charles W. Whittlesey led the 77th Division in a successful attack on German defenses in the Argonne Forest of northeastern France. His unit, comprised of men of a wide mix of ethnic backgrounds from New York City and the western states, was not a battalion nor was it ever "lost," but once a newspaper editor applied the term "lost battalion" to the episode, it stuck.

Gaff draws from new, unimpeachable sources—such as sworn testimony by soldiers who survived the ordeal—to correct the myths and legends and to reveal what really happened in the Argonne Forest during early October 1918.