In the first of a four-part series of the programme with a historical slant, Chris Eubank travels to Athens in Greece to search for the origins of the marathon, in the run-up to next weekend's race in London. Geneticist Steve Jones takes a trip to Iowa to recap on the first experiments to create hybrid crops and unravels a story that contains a warning about genetically modified food today. Presented by Mark Urban, with artist Ralph Steadman.
(Subtitled)