A secret room.  A walled up tomb.  A priceless jewel.  No, not on the set of the next Indiana Jones movie.  They lay hidden in America’s busiest railroad station. Train travel still thrives in New York City. Grand Central Terminal sees as many trains today as it did in the golden age of steam and steel. Picture the population of Atlanta and Buffalo pouring out of trains and subways. Seven hundred thousand travelers every day. Ten thousand pause to grab a meal, a thousand stop to ask directions. Some lose more than their way. In one month, train crews sent Grand Central’s Lost and Found three hundred cell phones, one hundred and fifty eyeglasses and an engagement ring.