Time travel classic - well done. Si Morley, an advertising executive in the early 1970’s - a man who draws the items for print ads - just a few years before computer graphics make him obsolete - is recruited into a government sponsored time travel experiment. After training, Si is able to return to the New York City of 1882. Using the Dakota as his “portal” - Si makes some tentative trips - with an eventual aim of finding out why his girlfriend Kate’s grandfather carried around a letter with a January 1882 NYC postmark until he committed suicide on a ranch in Montana early in the 20th century.