Tesla's Time Travelers

American history teacher Nathan Greene looked at the list of presidents on his bulletin board. How did Benedict Arnold become the second president of the United States? Who the heck was Shippen Jefferson? Where was John Adams? Had Greene and his high school students inadvertently changed history with their "field trip" to Philadelphia in 1776? There had been no such repercussions the previous spring when Greene took his class to Ford's Theater for the fateful performance of "Our American Cousin" on the evening of April 14, 1865. But somehow the Philadelphia field trip had caused a "butterfly effect" in the historical timeline, evicting John Adams from the White House and erasing the prominence of the Adams family from American history.Greene rued the day he purchased a strange box at a rummage sale at the Cassadaga Hotel—the cosmic center of Cassadaga, Florida, "The Psychic Capital of the World," and home to scores of psychics and a plethora of phantasms, including an overabundance of ghosts of deceased historians from Henry Adams to Howard Zinn.How was Greene to know that Nikola Tesla's prototype for a time travel device was a version of Pandora's box? Tesla's assembly instructions were a snap to follow, but something had gone wrong. What had they done? Therein lies the tale.