The Sixties were over. The Summer of Love, Haight-Ashbury, Woodstock, the Vietnam War were history. Nan, after an extended trip to Europe, was back in New York City, and Mark, awaiting his discharge from the army was living in Washington, D.C. They were planning a camping trip, via the Appalachian Trail and the Natchez Trace, to Mexico where they hoped to spend the coldest part of the winter. A chance meeting with a charismatic California couple had...