The Old Patagonian Express tells of Paul Theroux's train journey down the length of North and South America. Beginning on Boston's subway he depicts a voyage from ice-bound Massachusetts to the arid plateau of Argentina's most southerly tip. Shivering and sweating by turns as the temperature and altitude rise and plummet he describes the people he encountered - the tedious Mr Thornberry in Limon and reading to the legendary blind writer Jorge Luis Borges in Buenos Aires.