Time seemed to pass slowly on the train. It was winter and many of the cities we passed were obscured by the coal-burning fog that engulfs so much of China during the colder months.
The train that would take us from Shanghai to Tibet was itself thick with smoke of cigarette. Its occupants passed the time by playing cards, eating oranges, and shelling peanuts. Peanut shells and orange peels were piled on to metal trays given to passengers in lieu of trash cans. A faint but sweet smell of citrus lingered in the hallways.
The shortage of oxygen in the air is sudden and totalizing. I woke up on the evening of the second night unable to catch my breath. The train was mid-assent the highest line of track in the world. The Tanggula Pass at a altitude of 5,072 m (16,640 feet).