A simple telegram plunged America into the Great War. The Zimmermann telegram, intercepted by American intelligence in April 1917, revealed Germany’s efforts to encourage Mexico to invade the United States. For a towheaded kid from Arizona named Frank Luke, Jr., and other citizens of the states along the Mexican border, the threat of invasion was real and personal. The immigrants’ son Frank Luke, Jr. had a lot to prove when he joined the Army a few months later. If Frank Luke was going to prove anything, he needed to work fast.