The United States entered World War I in April 1917, and the war ended 19 months later.  Many elements of that war have been excluded from popular history – espionage and terrorism, both in Europe and on U.S. soil.  We’ll examine bomb plots, pencil bombs, an explosion that shook the Statue of Liberty, assassination, secret agents, German infiltration, and extraordinary people and events from the legend of Mata Hari, the sinking of the RMS Lusitania, and the man who became the “Father of American Cryptology.”